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Sample records for solid fuels kiinteiden

  1. Characterization of drying parameters for solid fuels; Kiinteiden polttoaineiden kuivumis-parametrien karakterisointi

    Energy Technology Data Exchange (ETDEWEB)

    Impola, R.; Saastamoinen, J. [VTT Energy, Jyvaeskylae (Finland); Fagernaes, L. [VTT Energy, Espoo (Finland)

    1997-12-01

    Drying of solid fuel particles in hot gases (50 - 200 deg C) is studied both theoretically and experimentally. The measurements are carried out by using a thermobalance reactor constructed for drying and pyrolysis studies of particles up to 30 mm by diameter. The model is based on the solution of the conservation equations for mass and energy. The main parameters affecting the drying rate are: particle size, particle shape, initial particle moisture content, gas temperature and gas moisture content, temperature of the reactor walls and slip velocity. Also, the drying of biomass fuel particles in fixed and moving beds with hot gas or steam is considered both experimentally and theoretically. A single particle drying model is coupled with a model describing heat and moisture transfer in the gas phase of the bed. The model can be used in the dimensioning of the drying system in a larger scale. Other study subjects were the movement of wood and peat particles in a pneumatic dryer, and the drying of a single fuel particle in steam under various pressures. The aim of the research work was to present a review of recent studies on emissions from biomass drying. The work covers the emissions from different feedstocks, and from different dryers and drying tests (atmospheric, pressurised, flue gas and steam drying), and the effects of factors, such as feedstock, dryer type and drying conditions, on the emissions. The formation and effects of the emissions, and methods to reduce them are also discussed

  2. Characterization of drying parameters for solid fuels; Kiinteiden polttoaineiden kuivumisparametrien karakterisointi

    Energy Technology Data Exchange (ETDEWEB)

    Impola, R. [VTT Energy, Jyvaeskylae (Finland). Fuels Production; Saastamoinen, J. [VTT Energy, Jyvaeskylae (Finland). Energy Production Technologies; Fagernaes, L. [VTT Energy, Espoo (Finland). Energy Production Technologies

    1995-12-31

    VTT Energy has investigated the drying technology of fuels for some years. The main focus has been on research of the fundamentals and modelling of the drying. Experimental research has been carried out using equipment of various sizes. The research has created profound information on the behaviour of fuels and on the reduction of emissions. Drying technology is a part of the quality control of biofuels and other moist in-homogeneous fuels before the combustion process. The drying of fuels influences operational behaviour and efficiency of the combustion equipment, dimensioning of the equipment and the reduction of emissions. New drying technologies make it possible to use new moist fuels and develop their production technologies. In this project VTT Energy has studied the factors influencing the drying, including drying of a single fuel particle in low temperatures (50-200 deg C) and the drying of a single fuel particle in steam under various pressures. Also, the drying of biomass fuel particles in fixed and moving beds with hot gas or steam is considered both experimentally and theoretically. A single particle drying model is coupled with a model describing heat and moisture transfer in the gas phase of the bed. The size of the bed to reach a certain degree of drying depends mostly on the following parameters: particle size, particle moisture content, gas inlet temperature, gas inlet moisture content and gas mass flow rate. As a special case, experiments simulating wood chip drying in a fixed bed and in counterflow were carried out. This research will also yield profound information on emissions of various dryer technologies and various fuels, as well as on factors influencing the emissions

  3. Cogasification of solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Green, A.; Jurczyk, K.; Mullin, J. [Univ. of Florida, Gainesville, FL (United States); Zanardi, M. [Sao Paulo State Univ., Guaratingueta, Sao Paulo (Brazil). Energy Dept.; Peres, S. [Univ. of Pernambuco, Recife (Brazil)

    1996-12-31

    High efficiency gas turbine based systems, utility deregulation and more stringent environmental regulations strongly favor the use of natural gas over coal and other solid fuels in new electricity generators. Solid fuels could continue to compete, however, if a low cost gasifier fed by low cost feedstocks can be coupled with a gas turbine system. The authors examine on-site gasification of coal with other domestic fuels in an indirectly heated gasifier as a strategy to lower the costs of solid fuel systems. The systematics of gaseous pyrolysis yields assembled with the help of thermal measurement data and molecular models suggests blending carbonaceous fuels such as coal, coke or char with oxygenated fuels such as biomass, RDF, MSW, or dried sewage sludge. Such solid fuel blending can, with the help of inexpensive catalysts, achieve an optimum balance of volatiles, heating values and residual char thus reducing the technical demands upon the gasifier. Such simplifications should lower capital and operating costs of the gasifier to the mutual benefit of both solid fuel communities.

  4. Solid Oxide Fuel Cell

    DEFF Research Database (Denmark)

    2010-01-01

    The solid oxide fuel cell comprising a metallic support material, an active anode layer consisting of a good hydrocarbon cracking catalyst, an electrolyte layer, an active cathode layer, and a transition layer consisting of preferably a mixture of LSM and a ferrite to the cathode current collector...

  5. Solid Oxide Fuel Cells

    Science.gov (United States)

    Brown, Jack T.

    Solid oxide fuel cells offer the potential for high efficiency, low cost electric power plants for many applications. The fuel cell generator Itself is an all solid state reactor operating at about 1000°C, which produces direct current electricity from the conversion of the energy in gaseous fuel by an electrochemical reaction with the oxygen in air. System studies have shown 50-60 percent efficiency can be obtained in multi-megawatt all electric power plants in which the high quality exhaust heat is used to produce electricity In a bottoming cycle. Alternatively the exhaust heat can be used in Industrial and commercial co-generation systems for space cooling or raising high pressure steam. Space based and military applications for electric power plants have been proposed with high power per unit weight and volume designs which use hydrogen fuel and pure oxygen. Truly significant accomplishments have been made in the 1980's in the technological development of the special materials and processes for producing them for the various cell designs and in the conception of device designs. These advancements were due to the fundamental work of the several decades earlier. In 1986 through 1988 experimental test units in the several hundred to several thousand watt sizes have been designed, fabricated, shipped, and tested for thousands of hours by user organizations in the United States and Japan. The extent of the commercial market for Solid Oxide fuel cells for various applications, vis-a-vis alternate electrical generation options, will depend on what system capital cost can be achieved.

  6. Oxidative pyrolysis of solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Senneca, Osvalda; Chirone, Riccardo [Istituto di Ricerche sulla Combustione, C.N.R., P.le Tecchio 80, 80125 Napoli (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, P.le Tecchio 80, 80125 Napoli (Italy)

    2004-06-01

    This study addresses the dependence of the rate and pattern of pyrolysis of solid fuels from the oxidizing versus inert nature of the gaseous atmosphere. A selection of four solid fuels is considered in the study, namely two plastics (polyethylene and polyethylene terephthalate), one lignocellulosic material (Robinia Pseudoacacia) and a South African bituminous coal. Fuels are pyrolyzed in a thermogravimetric apparatus at different heating rates, under inert conditions or in the presence of oxygen at different concentration.Results indicate that the action exerted by oxygen during pyrolysis depends on the nature of the fuel and on the process conditions such as heating rate and oxygen concentration. Larger heating rates and larger oxygen concentration may indeed emphasize differences between inert and oxidative pyrolysis. Further analysis is directed to check the adequacy of a power low kinetic expression to describe the dependence of the rate of oxidative pyrolysis from the level of oxygen concentration.

  7. Power generation from solid fuels

    CERN Document Server

    Spliethoff, Hartmut

    2010-01-01

    Power Generation from Solid Fuels introduces the different technologies to produce heat and power from solid fossil (hard coal, brown coal) and renewable (biomass, waste) fuels, such as combustion and gasification, steam power plants and combined cycles etc. The book discusses technologies with regard to their efficiency, emissions, operational behavior, residues and costs. Besides proven state of the art processes, the focus is on the potential of new technologies currently under development or demonstration. The main motivation of the book is to explain the technical possibilities for reduci

  8. Composite Solid Fuel: Research of Formation Parameters

    Directory of Open Access Journals (Sweden)

    Tabakaev Roman

    2016-01-01

    Full Text Available Involving of local low-grade fuels resources in fuel and energy balance is actual question of research in the present. In this paper the possibility of processing low-grade fuel in the solid fuel composite was considered. The aim of the work is to define the optimal parameters for formation of the solid composite fuel. A result of researches determined that dextrin content in the binder allows to obtain solid composite fuel having the highest strength. The drying temperature for the various fuels was determined: for pellets production was 20-80 °C, for briquettes – 20-40 °C.

  9. Gas transport in solid oxide fuel cells

    CERN Document Server

    He, Weidong; Dickerson, James

    2014-01-01

    This book provides a comprehensive overview of contemporary research and emerging measurement technologies associated with gas transport in solid oxide fuel cells. Within these pages, an introduction to the concept of gas diffusion in solid oxide fuel cells is presented. This book also discusses the history and underlying fundamental mechanisms of gas diffusion in solid oxide fuel cells, general theoretical mathematical models for gas diffusion, and traditional and advanced techniques for gas diffusivity measurement.

  10. Solid fuel applications to transportation engines

    Energy Technology Data Exchange (ETDEWEB)

    Rentz, Richard L.; Renner, Roy A.

    1980-06-01

    The utilization of solid fuels as alternatives to liquid fuels for future transportation engines is reviewed. Alternative liquid fuels will not be addressed nor will petroleum/solid fuel blends except for the case of diesel engines. With respect to diesel engines, coal/oil mixtures will be addressed because of the high interest in this specific application as a result of the large number of diesel engines currently in transportation use. Final assessments refer to solid fuels only for diesel engines. The technical assessments of solid fuels utilization for transportation engines is summarized: solid fuel combustion in transportation engines is in a non-developed state; highway transportation is not amenable to solid fuels utilization due to severe environmental, packaging, control, and disposal problems; diesel and open-cycle gas turbines do not appear worthy of further development, although coal/oil mixtures for slow speed diesels may offer some promise as a transition technology; closed-cycle gas turbines show some promise for solid fuels utilization for limited applications as does the Stirling engine for use of cleaner solid fuels; Rankine cycle engines show good potential for limited applications, such as for locomotives and ships; and any development program will require large resources and sophisticated equipment in order to advance the state-of-the-art.

  11. Energy properties of solid fossil fuels and solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    Holubcik, Michal, E-mail: michal.holubcik@fstroj.uniza.sk; Jandacka, Jozef, E-mail: jozef.jandacka@fstroj.uniza.sk [University of Žilina, Faculty of Mechanical Engineering, Department of Power Engineering, Univerzitná 8215/1, 010 26 Žilina (Slovakia); Kolkova, Zuzana, E-mail: zuzana.kolkova@rc.uniza.sk [Research centre, University of Žilina, Univerzitna 8215/1, 010 26 Žilina (Slovakia)

    2016-06-30

    The paper deals about the problematic of energy properties of solid biofuels in comparison with solid fossil fuels. Biofuels are alternative to fossil fuels and their properties are very similar. During the experiments were done in detail experiments to obtain various properties of spruce wood pellets and wheat straw pellets like biofuels in comparison with brown coal and black coal like fossil fuels. There were tested moisture content, volatile content, fixed carbon content, ash content, elementary analysis (C, H, N, S content) and ash fusion temperatures. The results show that biofuels have some advantages and also disadvantages in comparison with solid fossil fuels.

  12. Oxy-fuel combustion of solid fuels

    DEFF Research Database (Denmark)

    Toftegaard, Maja Bøg; Brix, Jacob; Jensen, Peter Arendt

    2010-01-01

    Oxy-fuel combustion is suggested as one of the possible, promising technologies for capturing CO2 from power plants. The concept of oxy-fuel combustion is removal of nitrogen from the oxidizer to carry out the combustion process in oxygen and, in most concepts, recycled flue gas to lower the flame...... provide additional options for improvement of process economics are however likewise investigated. Of particular interest is the change of the combustion process induced by the exchange of carbon dioxide and water vapor for nitrogen as diluent. This paper reviews the published knowledge on the oxy......-fuel process and focuses particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics. Knowledge is currently available regarding both an entire oxy-fuel power plant and the combustion fundamentals. However, several...

  13. The TMI regenerable solid oxide fuel cell

    Science.gov (United States)

    Cable, Thomas L.

    1995-04-01

    Energy storage and production in space requires rugged, reliable hardware which minimizes weight, volume, and maintenance while maximizing power output and usable energy storage. These systems generally consist of photovoltaic solar arrays which operate during sunlight cycles to provide system power and regenerate fuel (hydrogen) via water electrolysis; during dark cycles, hydrogen is converted by the fuel cell into system. The currently preferred configuration uses two separate systems (fuel cell and electrolyzer) in conjunction with photovoltaic cells. Fuel cell/electrolyzer system simplicity, reliability, and power-to-weight and power-to-volume ratios could be greatly improved if both power production (fuel cell) and power storage (electrolysis) functions can be integrated into a single unit. The Technology Management, Inc. (TMI), solid oxide fuel cell-based system offers the opportunity to both integrate fuel cell and electrolyzer functions into one unit and potentially simplify system requirements. Based an the TMI solid oxide fuel cell (SOPC) technology, the TMI integrated fuel cell/electrolyzer utilizes innovative gas storage and operational concepts and operates like a rechargeable 'hydrogen-oxygen battery'. Preliminary research has been completed on improved H2/H2O electrode (SOFC anode/electrolyzer cathode) materials for solid oxide, regenerative fuel cells. Improved H2/H2O electrode materials showed improved cell performance in both fuel cell and electrolysis modes in reversible cell tests. ln reversible fuel cell/electrolyzer mode, regenerative fuel cell efficiencies (ratio of power out (fuel cell mode) to power in (electrolyzer model)) improved from 50 percent (using conventional electrode materials) to over 80 percent. The new materials will allow the TMI SOFC system to operate as both the electrolyzer and fuel cell in a single unit. Preliminary system designs have also been developed which indicate the technical feasibility of using the TMI SOFC

  14. Interconnection of bundled solid oxide fuel cells

    Science.gov (United States)

    Brown, Michael; Bessette, II, Norman F; Litka, Anthony F; Schmidt, Douglas S

    2014-01-14

    A system and method for electrically interconnecting a plurality of fuel cells to provide dense packing of the fuel cells. Each one of the plurality of fuel cells has a plurality of discrete electrical connection points along an outer surface. Electrical connections are made directly between the discrete electrical connection points of adjacent fuel cells so that the fuel cells can be packed more densely. Fuel cells have at least one outer electrode and at least one discrete interconnection to an inner electrode, wherein the outer electrode is one of a cathode and and anode and wherein the inner electrode is the other of the cathode and the anode. In tubular solid oxide fuel cells the discrete electrical connection points are spaced along the length of the fuel cell.

  15. Solid oxide fuel cells fueled with reducible oxides

    Energy Technology Data Exchange (ETDEWEB)

    Chuang, Steven S.; Fan, Liang Shih

    2018-01-09

    A direct-electrochemical-oxidation fuel cell for generating electrical energy includes a cathode provided with an electrochemical-reduction catalyst that promotes formation of oxygen ions from an oxygen-containing source at the cathode, a solid-state reduced metal, a solid-state anode provided with an electrochemical-oxidation catalyst that promotes direct electrochemical oxidation of the solid-state reduced metal in the presence of the oxygen ions to produce electrical energy, and an electrolyte disposed to transmit the oxygen ions from the cathode to the solid-state anode. A method of operating a solid oxide fuel cell includes providing a direct-electrochemical-oxidation fuel cell comprising a solid-state reduced metal, oxidizing the solid-state reduced metal in the presence of oxygen ions through direct-electrochemical-oxidation to obtain a solid-state reducible metal oxide, and reducing the solid-state reducible metal oxide to obtain the solid-state reduced metal.

  16. Jet Fuel Based High Pressure Solid Oxide Fuel Cell System

    Science.gov (United States)

    Gummalla, Mallika (Inventor); Yamanis, Jean (Inventor); Olsommer, Benoit (Inventor); Dardas, Zissis (Inventor); Bayt, Robert (Inventor); Srinivasan, Hari (Inventor); Dasgupta, Arindam (Inventor); Hardin, Larry (Inventor)

    2015-01-01

    A power system for an aircraft includes a solid oxide fuel cell system which generates electric power for the aircraft and an exhaust stream; and a heat exchanger for transferring heat from the exhaust stream of the solid oxide fuel cell to a heat requiring system or component of the aircraft. The heat can be transferred to fuel for the primary engine of the aircraft. Further, the same fuel can be used to power both the primary engine and the SOFC. A heat exchanger is positioned to cool reformate before feeding to the fuel cell. SOFC exhaust is treated and used as inerting gas. Finally, oxidant to the SOFC can be obtained from the aircraft cabin, or exterior, or both.

  17. Solid polymer MEMS-based fuel cells

    Science.gov (United States)

    Jankowski, Alan F [Livermore, CA; Morse, Jeffrey D [Pleasant Hill, CA

    2008-04-22

    A micro-electro-mechanical systems (MEMS) based thin-film fuel cells for electrical power applications. The MEMS-based fuel cell may be of a solid oxide type (SOFC), a solid polymer type (SPFC), or a proton exchange membrane type (PEMFC), and each fuel cell basically consists of an anode and a cathode separated by an electrolyte layer. The electrolyte layer can consist of either a solid oxide or solid polymer material, or proton exchange membrane electrolyte materials may be used. Additionally catalyst layers can also separate the electrodes (cathode and anode) from the electrolyte. Gas manifolds are utilized to transport the fuel and oxidant to each cell and provide a path for exhaust gases. The electrical current generated from each cell is drawn away with an interconnect and support structure integrated with the gas manifold. The fuel cells utilize integrated resistive heaters for efficient heating of the materials. By combining MEMS technology with thin-film deposition technology, thin-film fuel cells having microflow channels and full-integrated circuitry can be produced that will lower the operating temperature an will yield an order of magnitude greater power density than the currently known fuel cells.

  18. Solid Acid Based Fuel Cells

    National Research Council Canada - National Science Library

    Haile, Sossina M

    2005-01-01

    ...) without pressurization. In this configuration, the thin-film fuel cell is supported on a porous stainless steel gas diffusion layer and the electrocatalyst and electrolyte layers are spray-deposited...

  19. Fuel utilization and fuel sensitivity of solid oxide fuel cells

    Science.gov (United States)

    Huang, Kevin

    2011-03-01

    Fuel utilization and fuel sensitivity are two important process variables widely used in operation of SOFC cells, stacks, and generators. To illustrate the technical values, the definitions of these two variables as well as practical examples are particularly given in this paper. It is explicitly shown that the oxygen-leakage has a substantial effect on the actual fuel utilization, fuel sensitivity and V-I characteristics. An underestimation of the leakage flux could potentially results in overly consuming fuel and oxidizing Ni-based anode. A fuel sensitivity model is also proposed to help extract the leakage flux information from a fuel sensitivity curve. Finally, the "bending-over" phenomenon observed in the low-current range of a V-I curve measured at constant fuel-utilization is quantitatively coupled with leakage flux.

  20. Solid Oxide Fuel Cells Operating on Alternative and Renewable Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xiaoxing; Quan, Wenying; Xiao, Jing; Peduzzi, Emanuela; Fujii, Mamoru; Sun, Funxia; Shalaby, Cigdem; Li, Yan; Xie, Chao; Ma, Xiaoliang; Johnson, David; Lee, Jeong; Fedkin, Mark; LaBarbera, Mark; Das, Debanjan; Thompson, David; Lvov, Serguei; Song, Chunshan

    2014-09-30

    This DOE project at the Pennsylvania State University (Penn State) initially involved Siemens Energy, Inc. to (1) develop new fuel processing approaches for using selected alternative and renewable fuels – anaerobic digester gas (ADG) and commercial diesel fuel (with 15 ppm sulfur) – in solid oxide fuel cell (SOFC) power generation systems; and (2) conduct integrated fuel processor – SOFC system tests to evaluate the performance of the fuel processors and overall systems. Siemens Energy Inc. was to provide SOFC system to Penn State for testing. The Siemens work was carried out at Siemens Energy Inc. in Pittsburgh, PA. The unexpected restructuring in Siemens organization, however, led to the elimination of the Siemens Stationary Fuel Cell Division within the company. Unfortunately, this led to the Siemens subcontract with Penn State ending on September 23rd, 2010. SOFC system was never delivered to Penn State. With the assistance of NETL project manager, the Penn State team has since developed a collaborative research with Delphi as the new subcontractor and this work involved the testing of a stack of planar solid oxide fuel cells from Delphi.

  1. Solid oxide fuel cell with monolithic core

    Science.gov (United States)

    McPheeters, C.C.; Mrazek, F.C.

    1988-08-02

    A solid oxide fuel cell in which fuel and oxidant gases undergo an electrochemical reaction to produce an electrical output includes a monolithic core comprised of a corrugated conductive sheet disposed between upper and lower generally flat sheets. The corrugated sheet includes a plurality of spaced, parallel, elongated slots which form a series of closed, linear, first upper and second lower gas flow channels with the upper and lower sheets within which a fuel gas and an oxidant gas respectively flow. Facing ends of the fuel cell are generally V-shaped and provide for fuel and oxidant gas inlet and outlet flow, respectively, and include inlet and outlet gas flow channels which are continuous with the aforementioned upper fuel gas and lower oxidant gas flow channels. The upper and lower flat sheets and the intermediate corrugated sheet are preferably comprised of ceramic materials and are securely coupled together such as by assembly in the green state and sintering together during firing at high temperatures. A potential difference across the fuel cell, or across a stacked array of similar fuel cells, is generated when an oxidant gas such as air and a fuel such as hydrogen gas is directed through the fuel cell at high temperatures, e.g., between 700 C and 1,100 C. 8 figs.

  2. Use of alternative fuels in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2007-05-15

    A future sustainable energy system will certainly be based on a variety of environmentally benign energy production technologies. Fuel cells can be a key element in this scenario. One of the fuel cells types the solid oxide fuel cell (SOFC) has a number of advantages that places them in a favorable position: high efficiency, parallel production of electricity and high value heat, prevention of NOx emission, flexibility regarding usable fuels, and certain tolerance towards impurities. It is thus a natural option, to combine such a highly efficient energy conversion tool with a sustainable fuel supply. In the present contribution, the use of alternative compared to conventional fuels in SOFCs was evaluated. Regarding carbon containing, biomass derived fuels, SOFCs showed excellent power output and stability behavior during long-term testing under technologically relevant conditions. Moreover, ammonia can be used directly as fuel. The chemical and structural properties of the SOFC anode makes it even possible, to combine a chemical conversion of the fuel, for example methane into synthesis gas via steam reforming and decomposition of ammonia into hydrogen and nitrogen, with the electrochemical production of electricity in one step. (au)

  3. Sealant materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Krumpelt, M.

    1995-08-01

    The objective of this work is to complete the development of soft glass-ceramic sealants for the solid oxide fuel cell (SOFC). Among other requirements, the materials must soften at the operation temperature of the fuel cell (600-1000{degrees}C) to relieve stresses between stack components, and their thermal expansions must be tailored to match those of the stack materials. Specific objectives included addressing the needs of industrial fuel cell developers, based on their evaluation of samples we supply, as well as working with commercial glass producers to achieve scaled-up production of the materials without changing their properties.

  4. Mathematical modeling of solid oxide fuel cells

    Science.gov (United States)

    Lu, Cheng-Yi; Maloney, Thomas M.

    1988-01-01

    Development of predictive techniques, with regard to cell behavior, under various operating conditions is needed to improve cell performance, increase energy density, reduce manufacturing cost, and to broaden utilization of various fuels. Such technology would be especially beneficial for the solid oxide fuel cells (SOFC) at it early demonstration stage. The development of computer models to calculate the temperature, CD, reactant distributions in the tubular and monolithic SOFCs. Results indicate that problems of nonuniform heat generation and fuel gas depletion in the tubular cell module, and of size limitions in the monolithic (MOD 0) design may be encountered during FC operation.

  5. Solid oxide fuel cell process and apparatus

    Science.gov (United States)

    Cooper, Matthew Ellis [Morgantown, WV; Bayless, David J [Athens, OH; Trembly, Jason P [Durham, NC

    2011-11-15

    Conveying gas containing sulfur through a sulfur tolerant planar solid oxide fuel cell (PSOFC) stack for sulfur scrubbing, followed by conveying the gas through a non-sulfur tolerant PSOFC stack. The sulfur tolerant PSOFC stack utilizes anode materials, such as LSV, that selectively convert H.sub.2S present in the fuel stream to other non-poisoning sulfur compounds. The remaining balance of gases remaining in the completely or near H.sub.2S-free exhaust fuel stream is then used as the fuel for the conventional PSOFC stack that is downstream of the sulfur-tolerant PSOFC. A broad range of fuels such as gasified coal, natural gas and reformed hydrocarbons are used to produce electricity.

  6. Nanocrystalline cerium oxide materials for solid fuel cell systems

    Science.gov (United States)

    Brinkman, Kyle S

    2015-05-05

    Disclosed are solid fuel cells, including solid oxide fuel cells and PEM fuel cells that include nanocrystalline cerium oxide materials as a component of the fuel cells. A solid oxide fuel cell can include nanocrystalline cerium oxide as a cathode component and microcrystalline cerium oxide as an electrolyte component, which can prevent mechanical failure and interdiffusion common in other fuel cells. A solid oxide fuel cell can also include nanocrystalline cerium oxide in the anode. A PEM fuel cell can include cerium oxide as a catalyst support in the cathode and optionally also in the anode.

  7. Thin-Film Solid Oxide Fuel Cells

    Science.gov (United States)

    Chen, Xin; Wu, Nai-Juan; Ignatiev, Alex

    2009-01-01

    The development of thin-film solid oxide fuel cells (TFSOFCs) and a method of fabricating them have progressed to the prototype stage. This can result in the reduction of mass, volume, and the cost of materials for a given power level.

  8. Near-ambient solid polymer fuel cell

    Science.gov (United States)

    Holleck, G. L.

    1993-01-01

    Fuel cells are extremely attractive for extraterrestrial and terrestrial applications because of their high energy conversion efficiency without noise or environmental pollution. Among the various fuel cell systems the advanced polymer electrolyte membrane fuel cells based on sulfonated fluoropolymers (e.g., Nafion) are particularly attractive because they are fairly rugged, solid state, quite conductive, of good chemical and thermal stability and show good oxygen reduction kinetics due to the low specific adsorption of the electrolyte on the platinum catalyst. The objective of this program is to develop a solid polymer fuel cell which can efficiently operate at near ambient temperatures without ancillary components for humidification and/or pressurization of the fuel or oxidant gases. During the Phase 1 effort we fabricated novel integral electrode-membrane structures where the dispersed platinum catalyst is precipitated within the Nafion ionomer. This resulted in electrode-membrane units without interfacial barriers permitting unhindered water diffusion from cathode to anode. The integral electrode-membrane structures were tested as fuel cells operating on H2 and O2 or air at 1 to 2 atm and 10 to 50 C without gas humidification. We demonstrated that cells with completely dry membranes could be self started at room temperature and subsequently operated on dry gas for extended time. Typical room temperature low pressure operation with unoptimized electrodes yielded 100 mA/cm(exp 2) at 0.5V and maximum currents over 300 mA/cm(exp 2) with low platinum loadings. Our results clearly demonstrate that operation of proton exchange membrane fuel cells at ambient conditions is feasible. Optimization of the electrode-membrane structure is necessary to assess the full performance potential but we expect significant gains in weight and volume power density for the system. The reduced complexity will make fuel cells also attractive for smaller and portable power supplies and as

  9. On computation of solid fuel regression rate in ramjet combustor

    Science.gov (United States)

    Razmyslov, A. V.; Yanovskiy, L. S.; Toktaliev, P. D.

    2017-11-01

    Development of a solid fuel ramjets requires mathematical modeling of the solid fuel regression inside a combustor with accounting of solid fuel gasification and combustion processes and a numerical method to calculate parameters of these processes. This report presents a quasi-one-dimensional model of processes inside the solid fuel ramjet combustor. The model allows to calculate the solid fuel regression rate and gas flow parameters at the combustor outlet while air flow parameters at the combustor inlet are fixed. The model is based on mass, energy, species and momentum conservation equations and deals with thermochemical processes inside the ramjet combustor. It considers gas flow inside the combustor, gasified fuel combustion, convective heat transfer, solid fuel pyrolysis kinetics. The model is verified by comparison of the numerical results with the experimental data available from other authors. The analysis of the numerical results shows a dependence of the flow structure and thermochemical parameters of a solid fuel employed on the regression rate.

  10. Fire Hazards of Some Modern Solid Fuels

    Directory of Open Access Journals (Sweden)

    Vasily Novozhilov

    2017-01-01

    Full Text Available Fire hazard during ship transportation of certain modern solid fuels is identified. A particular mechanism which may lead to catastrophic ship fire is discussed. A mathematical model predicting time to such fully developed fire (flashover time I s proposed. An analytical solution is obtained for the developed model. An important part of this solution is a closed form analytical description of the smoke filling dynamics in a closed compartment. It is demonstrated that flashover time depends on a number of parameters. The relative importance of these parameters is discussed. Particular significance is attributed to fuel soot propensity (fuel soot yield which is an intrinsic fuel property. This parameter controls the intensity of radiative heat exchange in the compartment, and its influence on flashover time is of paramount importance. It is suggested that fuels are ranked with respect to this parameter in order to describe their relative fire hazards. This ranking should be implemented into the regulatory framework governing fuel transportation by ships.

  11. Stability of solid oxide fuel cell materials

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.R.; Bates, J.L.; Chick, L.A. [Pacific Northwest Lab., Richland, WA (United States)

    1996-04-01

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

  12. Addressing fuel recycling in solid oxide fuel cell systems fed by alternative fuels

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2017-01-01

    An innovative study on anode recirculation in solid oxide fuel cell systems with alternative fuels is carried out and investigated. Alternative fuels under study are ammonia, pure hydrogen, methanol, ethanol, DME and biogas from biomass gasification. It is shown that the amount of anode off-fuel...... recirculation depends strongly on type of the fuel used in the system. Anode recycling combined with fuel cell utilization factors have an important impact on plant efficiency, which will be analysed here. The current study may provide an in-depth understanding of reasons for using anode off-fuel recycling...... and its effect on plant efficiency. For example, it is founded that anode recirculation is not needed when the plant is fed by ammonia. Further, it is founded that when the system is fed by pure hydrogen then anode recirculation should be about 20% of the off-fuel if fuel cell utilization factor is 80...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2003-12-08

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

  14. Direct Carbon Fuel Cell System Utilizing Solid Carbonaceous Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Turgut Gur

    2010-04-30

    This 1-year project has achieved most of its objective and successfully demonstrated the viability of the fluidized bed direct carbon fuel cell (FB-DCFC) approach under development by Direct Carbon technologies, LLC, that utilizes solid carbonaceous fuels for power generation. This unique electrochemical technology offers high conversion efficiencies, produces proportionately less CO{sub 2} in capture-ready form, and does not consume or require water for gasification. FB-DCFC employs a specialized solid oxide fuel cell (SOFC) arrangement coupled to a Boudouard gasifier where the solid fuel particles are fluidized and reacted by the anode recycle gas CO{sub 2}. The resulting CO is electrochemically oxidized at the anode. Anode supported SOFC structures employed a porous Ni cermet anode layer, a dense yttria stabilized zirconia membrane, and a mixed conducting porous perovskite cathode film. Several kinds of untreated solid fuels (carbon and coal) were tested in bench scale FBDCFC prototypes for electrochemical performance and stability testing. Single cells of tubular geometry with active areas up to 24 cm{sup 2} were fabricated. The cells achieved high power densities up to 450 mW/cm{sup 2} at 850 C using a low sulfur Alaska coal char. This represents the highest power density reported in the open literature for coal based DCFC. Similarly, power densities up to 175 mW/cm{sup 2} at 850 C were demonstrated with carbon. Electrical conversion efficiencies for coal char were experimentally determined to be 48%. Long-term stability of cell performance was measured under galvanostatic conditions for 375 hours in CO with no degradation whatsoever, indicating that carbon deposition (or coking) does not pose any problems. Similar cell stability results were obtained in coal char tested for 24 hours under galvanostatic conditions with no sign of sulfur poisoning. Moreover, a 50-cell planar stack targeted for 1 kW output was fabricated and tested in 95% CO (balance CO{sub 2

  15. Durability of solid oxide fuel cells using sulfur containing fuels

    DEFF Research Database (Denmark)

    Hagen, Anke; Rasmussen, Jens Foldager Bregnballe; Thydén, Karl Tor Sune

    2011-01-01

    The usability of hydrogen and also carbon containing fuels is one of the important advantages of solid oxide fuel cells (SOFCs), which opens the possibility to use fuels derived from conventional sources such as natural gas and from renewable sources such as biogas. Impurities like sulfur compounds...... are critical in this respect. State-of-the-art Ni/YSZ SOFC anodes suffer from being rather sensitive towards sulfur impurities. In the current study, anode supported SOFCs with Ni/YSZ or Ni/ScYSZ anodes were exposed to H2S in the ppm range both for short periods of 24h and for a few hundred hours. In a fuel...... to a loss of percolation of Ni particles in the Ni/YSZ anode layers closest to the electrolyte. Using SOFCs with Ni/ScYSZ anodes improved the H2S tolerance considerably, even at larger H2S concentrations of 10 and 20ppm over a few hundred hours....

  16. A review of liquid metal anode solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    ALIYA TOLEUOVA

    2013-06-01

    Full Text Available This review discusses recent advances in a solid oxide fuel cell (SOFC variant that uses liquid metal electrodes (anodes with the advantage of greater fuel tolerance and the ability to operate on solid fuel. Key features of the approach are discussed along with the technological and research challenges that need to be overcome for scale-up and commercialisation.

  17. Topology Optimization of Solid Oxide Fuel Cells

    Science.gov (United States)

    Panagakos, Grigorios; Okkels, Fridolin

    2010-11-01

    We present a free form optimization of Solid Oxide Fuel Cell models, using a high-level implementation of topology optimization according to [1]. As a first step towards the cell's full optimization, we focus in the design of the interconnect. The interconnect is a key element of the whole cell as it is responsible for separating the anode of one cell from the cathode of its next one in a stack of cells, thus being responsible for the supply of fuel and cooling gases, securing in the same time the efficient conductance of electrons through the stack. Modeling the steady-state operation of a fuel cell incorporates the coupling between different physics, such as reaction, electronic, ionic, thermal and fluid phenomena, and is adequately described in two dimensions. Different objective functions, guiding the optimization method, are being investigated, such like the cell's and interconnect's efficiency, heat convection rate and the inlet flowrates of fuel and cooling gases. [4pt] [1] L.H. Olesen, F. Okkels, and H. Bruus, Int. J. Num. Meth. Eng. 65, 975 (2006).

  18. Tubular solid oxide fuel cell demonstration activities

    Energy Technology Data Exchange (ETDEWEB)

    Veyo, S.E.

    1995-08-01

    The development of a viable fuel cell driven electrical power generation system involves not only the development of cell and stack technology, but also the development of the overall system concept, the strategy for control, and the ancillary subsystems. The design requirements used to guide system development must reflect a customer focus in order to evolve a commercial product. In order to obtain useful customer feedback, Westinghouse has practiced the deployment with customers of fully integrated, automatically controlled, packaged solid oxide fuel cell power generation systems. These field units have served to demonstrate to customers first hand the beneficial attributes of the SOFC, to expose deficiencies through experience in order to guide continued development, and to garner real world feedback and data concerning not only cell and stack parameters, but also transportation, installation, permitting and licensing, start-up and shutdown, system alarming, fault detection, fault response, and operator interaction.

  19. Solid fuel grindability: a literature review

    Energy Technology Data Exchange (ETDEWEB)

    Hills, L.

    2007-07-01

    The most commonly used measurement of coal grindability is the Hardgrove Grindability Index (HGI) however, many solid fuels do not exhibit the grinding performance predicted by this index. Parameters which can influence grindability and possibly lead to inaccurate prediction of grindability as determined by HGI include: composition and texture, mineral components, brittleness, and rank (which establishes carbon, volatile matter, and moisture contents). Descriptions of these parameters are provided. Alternative measurements of grindability from literature are presented. The most promising may be a revision on the standard HGI, in which a mill capacity factor is derived from the number of mill rotations to crush coal to a specific fineness. 88 refs.

  20. Tubular solid oxide fuel cell development program

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-08-01

    This paper presents an overview of the Westinghouse Solid Oxide Fuel Cell (SOFC) development activities and current program status. The Westinghouse goal is to develop a cost effective cell that can operate for 50,000 to 100,000 hours. Progress toward this goal will be discussed and test results presented for multiple single cell tests which have now successfully exceeded 56,000 hours of continuous power operation at temperature. Results of development efforts to reduce cost and increase power output of tubular SOFCs are described.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-05-07

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

  2. Monolithic Solid Oxide Fuel Cell development

    Science.gov (United States)

    Myles, K. M.; McPheeters, C. C.

    1989-12-01

    The Monolithic Solid Oxide Fuel Cell (MSOFC) is an oxide-ceramic structure in which appropriate electronic and ionic conductors are fabricated in a honeycomb shape similar to a block of corrugated paperboard. These electronic and ionic conductors are arranged to provide short conduction paths to minimize resistive losses. The power density achievable with the MSOFC is expected to be about 8 kW/kg or 4 kW/L, at fuel efficienceis over 50 percent, because of small cell size and low resistive losses in the materials. The MSOFC operates in the range of 700 to 1000 C, at which temperatures rapid reform of hydrocarbon fuels is expected within the nickel-YSZ fuel channels. Tape casting and hot roll calendering are used to fabricate the MSOFC structure. The performance of the MSOFC has improved significantly during the course of development. The limitation of this system, based on materials resistance alone without interfacial resistances, is 0.093 ohm-sq cm area-specific resistance (ASR). The current typical performance of MSOFC single cells is characterized by ASRs of about 0.4 to 0.5 ohm-sq cm. With further development the ASR is expected to be reduced below 0.2 ohm-sq cm, which will result in power levels greater than 1.4 W/sq cm. The feasibility of the MSOFC concept was proven, and the performance was dramatically improved. The differences in thermal expansion coefficients and firing shrinkages among the fuel cell materials were minimized. As a result of good matching of these properties, the MSOFC structure was successfully fabricated with few defects, and the system shows excellent promise for development into a practical power source.

  3. Engineered glass seals for solid-oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Surdoval, Wayne; Lara-Curzio, Edgar; Stevenson, Jeffry; Muth, Joseph Thomas; Armstrong, Beth L.; Shyam, Amit; Trejo, Rosa M.; Wang, Yanli; Chou, Yeong Shyung; Shultz, Travis Ray

    2017-02-07

    A seal for a solid oxide fuel cell includes a glass matrix having glass percolation therethrough and having a glass transition temperature below 650.degree. C. A deformable second phase material is dispersed in the glass matrix. The second phase material can be a compliant material. The second phase material can be a crushable material. A solid oxide fuel cell, a precursor for forming a seal for a solid oxide fuel cell, and a method of making a seal for a solid oxide fuel cell are also disclosed.

  4. Solid-polymer-electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, T.F.

    1992-07-01

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25{degrees}C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich's solution and analysis.

  5. Solid-polymer-electrolyte fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Fuller, Thomas F. [Univ. of California, Berkeley, CA (United States)

    1992-07-01

    A transport model for polymer electrolytes is presented, based on concentrated solution theory and irreversible thermodynamics. Thermodynamic driving forces are developed, transport properties are identified and experiments devised. Transport number of water in Nafion 117 membrane is determined using a concentration cell. It is 1.4 for a membrane equilibrated with saturated water vapor at 25°C, decreases slowly as the membrane is dehydrated, and falls sharply toward zero as the water content approaches zero. The relation between transference number, transport number, and electroosmotic drag coefficient is presented, and their relevance to water-management is discussed. A mathematical model of transport in a solid-polymer-electrolyte fuel cell is presented. A two-dimensional membrane-electrode assembly is considered. Water management, thermal management, and utilization of fuel are examined in detail. The membrane separators of these fuel cells require sorbed water to maintain conductivity; therefore it is necessary to manage the water content in membranes to ensure efficient operation. Water and thermal management are interrelated. Rate of heat removal is shown to be a critical parameter in the operation of these fuel cells. Current-voltage curves are presented for operation on air and reformed methanol. Equations for convective diffusion to a rotating disk are solved numerically for a consolute point between the bulk concentration and the surface. A singular-perturbation expansion is presented for the condition where the bulk concentration is nearly equal to the consolute-point composition. Results are compared to Levich`s solution and analysis.

  6. Fixed bed gasification of solid biomass fuels

    Energy Technology Data Exchange (ETDEWEB)

    Haavisto, I. [Condens Oy, Haemeenlinna (Finland)

    1996-12-31

    Fixed bed biomass gasifiers are feasible in the effect range of 100 kW -10 MW. Co-current gasification is available only up to 1 MW for technical reasons. Counter-current gasifiers have been used in Finland and Sweden for 10 years in gasification heating plants, which are a combination of a gasifier and an oil boiler. The plants have proved to have a wide control range, flexible and uncomplicated unmanned operation and an excellent reliability. Counter-current gasifiers can be applied for new heating plants or for converting existing oil and natural gas boilers into using solid fuels. There is a new process development underway, aiming at motor use of the producer gas. The development work involves a new, more flexible cocurrent gasifier and a cleaning step for the counter-current producer gas. (orig.)

  7. Solid oxide fuel cell power system development

    Energy Technology Data Exchange (ETDEWEB)

    Kerr, Rick [Delphi Automotive Systems, LLC., Troy, MI (United States); Wall, Mark [Independent Energy Partners Technology, LLC., Parker, CO (United States); Sullivan, Neal [Colorado School of Mines, Golden, CO (United States)

    2015-06-26

    This report summarizes the progress made during this contractual period in achieving the goal of developing the solid oxide fuel cell (SOFC) cell and stack technology to be suitable for use in highly-efficient, economically-competitive, commercially deployed electrical power systems. Progress was made in further understanding cell and stack degradation mechanisms in order to increase stack reliability toward achieving a 4+ year lifetime, in cost reduction developments to meet the SECA stack cost target of $175/kW (in 2007 dollars), and in operating the SOFC technology in a multi-stack system in a real-world environment to understand the requirements for reliably designing and operating a large, stationary power system.

  8. Nanostructured Solid Oxide Fuel Cell Electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Sholklapper, Tal Zvi [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    The ability of Solid Oxide Fuel Cells (SOFC) to directly and efficiently convert the chemical energy in hydrocarbon fuels to electricity places the technology in a unique and exciting position to play a significant role in the clean energy revolution. In order to make SOFC technology cost competitive with existing technologies, the operating temperatures have been decreased to the range where costly ceramic components may be substituted with inexpensive metal components within the cell and stack design. However, a number of issues have arisen due to this decrease in temperature: decreased electrolyte ionic conductivity, cathode reaction rate limitations, and a decrease in anode contaminant tolerance. While the decrease in electrolyte ionic conductivities has been countered by decreasing the electrolyte thickness, the electrode limitations have remained a more difficult problem. Nanostructuring SOFC electrodes addresses the major electrode issues. The infiltration method used in this dissertation to produce nanostructure SOFC electrodes creates a connected network of nanoparticles; since the method allows for the incorporation of the nanoparticles after electrode backbone formation, previously incompatible advanced electrocatalysts can be infiltrated providing electronic conductivity and electrocatalysis within well-formed electrolyte backbones. Furthermore, the method is used to significantly enhance the conventional electrode design by adding secondary electrocatalysts. Performance enhancement and improved anode contamination tolerance are demonstrated in each of the electrodes. Additionally, cell processing and the infiltration method developed in conjunction with this dissertation are reviewed.

  9. Intermediate Temperature Solid Oxide Fuel Cell Development

    Energy Technology Data Exchange (ETDEWEB)

    S. Elangovan; Scott Barnett; Sossina Haile

    2008-06-30

    Solid oxide fuel cells (SOFCs) are high efficiency energy conversion devices. Present materials set, using yttria stabilized zirconia (YSZ) electrolyte, limit the cell operating temperatures to 800 C or higher. It has become increasingly evident however that lowering the operating temperature would provide a more expeditious route to commercialization. The advantages of intermediate temperature (600 to 800 C) operation are related to both economic and materials issues. Lower operating temperature allows the use of low cost materials for the balance of plant and limits degradation arising from materials interactions. When the SOFC operating temperature is in the range of 600 to 700 C, it is also possible to partially reform hydrocarbon fuels within the stack providing additional system cost savings by reducing the air preheat heat-exchanger and blower size. The promise of Sr and Mg doped lanthanum gallate (LSGM) electrolyte materials, based on their high ionic conductivity and oxygen transference number at the intermediate temperature is well recognized. The focus of the present project was two-fold: (a) Identify a cell fabrication technique to achieve the benefits of lanthanum gallate material, and (b) Investigate alternative cathode materials that demonstrate low cathode polarization losses at the intermediate temperature. A porous matrix supported, thin film cell configuration was fabricated. The electrode material precursor was infiltrated into the porous matrix and the counter electrode was screen printed. Both anode and cathode infiltration produced high performance cells. Comparison of the two approaches showed that an infiltrated cathode cells may have advantages in high fuel utilization operations. Two new cathode materials were evaluated. Northwestern University investigated LSGM-ceria composite cathode while Caltech evaluated Ba-Sr-Co-Fe (BSCF) based pervoskite cathode. Both cathode materials showed lower polarization losses at temperatures as low as 600

  10. Advanced materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.R.; Stevenson, J.

    1995-08-01

    The purpose of this research is to improve the properties of the current state-of-the-art materials used for solid oxide fuel cells (SOFCs). The objectives are to: (1) develop materials based on modifications of the state-of-the-art materials; (2) minimize or eliminate stability problems in the cathode, anode, and interconnect; (3) Electrochemically evaluate (in reproducible and controlled laboratory tests) the current state-of-the-art air electrode materials and cathode/electrolyte interfacial properties; (4) Develop accelerated electrochemical test methods to evaluate the performance of SOFCs under controlled and reproducible conditions; and (5) Develop and test materials for use in low-temperature SOFCs. The goal is to modify and improve the current state-of-the-art materials and minimize the total number of cations in each material to avoid negative effects on the materials properties. Materials to reduce potential deleterious interactions, (3) improve thermal, electrical, and electrochemical properties, (4) develop methods to synthesize both state-of-the-art and alternative materials for the simultaneous fabricatoin and consolidation in air of the interconnections and electrodes with the solid electrolyte, and (5) understand electrochemical reactions at materials interfaces and the effects of component composition and processing on those reactions.

  11. Advanced methods of solid oxide fuel cell modeling

    CERN Document Server

    Milewski, Jaroslaw; Santarelli, Massimo; Leone, Pierluigi

    2011-01-01

    Fuel cells are widely regarded as the future of the power and transportation industries. Intensive research in this area now requires new methods of fuel cell operation modeling and cell design. Typical mathematical models are based on the physical process description of fuel cells and require a detailed knowledge of the microscopic properties that govern both chemical and electrochemical reactions. ""Advanced Methods of Solid Oxide Fuel Cell Modeling"" proposes the alternative methodology of generalized artificial neural networks (ANN) solid oxide fuel cell (SOFC) modeling. ""Advanced Methods

  12. Stability of solid oxide fuel cell materials

    Energy Technology Data Exchange (ETDEWEB)

    Armstrong, T.R.; Bates, J.L.; Coffey, G.W.; Pederson, L.R. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

    1996-08-01

    Chromite interconnection materials in an SOFC are exposed to both highly oxidizing conditions at the cathode and to highly reducing conditions at the anode. Because such conditions could lead to component failure, the authors have evaluated thermal, electrical, chemical, and structural stabilities of these materials as a function of temperature and oxygen partial pressure. The crystal lattice of the chromites was shown to expand for oxygen partial pressures smaller than 10{sup {minus}10} atm, which could lead to cracking and debonding in an SOFC. Highly substituted lanthanum chromite compositions were the most susceptible to lattice expansion; yttrium chromites showed better dimensional stability by more than a factor of two. New chromite compositions were developed that showed little tendency for lattice expansion under strongly reducing conditions, yet provided a good thermal expansion match to other fuel cell components. Use of these new chromite interconnect compositions should improve long-term SOFC performance, particularly for planar cell configurations. Thermodynamic properties of substituted lanthanum manganite cathode compositions have been determined through measurement of electromotive force as a function of temperature. Critical oxygen decomposition pressures for Sr and Ca-substituted lanthanum manganites were established using cells based on a zirconia electrolyte. Strontium oxide and calcium oxide activities in a lanthanum manganite matrix were determined using cells based on strontium fluoride and calcium fluoride electrolytes, respectively. The compositional range of single-phase behavior of these ABO{sub 3}-type perovskites was established as a function of A/B cation ratios and the extent of acceptor doping. Before this work, very little thermodynamic information was in existence for substituted manganite compositions. Such information is needed to predict the long-term stability of solid oxide fuel cell assemblies.

  13. Biomass Conversion into Solid Composite Fuel for Bed-Combustion

    Directory of Open Access Journals (Sweden)

    Tabakaev Roman B.

    2015-01-01

    Full Text Available The purpose of this research is the conversion of different types of biomass into solid composite fuel. The subject of research is the heat conversion of biomass into solid composite fuel. The research object is the biomass of the Tomsk region (Russia: peat, waste wood, lake sapropel. Physical experiment of biomass conversion is used as method of research. The new experimental unit for thermal conversion of biomass into carbon residue, fuel gas and pyrolysis condensate is described. As a result of research such parameters are obtained: thermotechnical biomass characteristics, material balances and product characteristics of the heat-technology conversion. Different methods of obtaining solid composite fuel from the products of thermal technologies are considered. As a result, it is established: heat-technology provides efficient conversion of the wood chips and peat; conversion of the lake sapropel is inefficient since the solid composite fuel has the high ash content and net calorific value.

  14. Sealing materials for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Larsen, P.H.

    1999-02-01

    A major obstacle in the achievement of high electrical efficiency for planar solid oxide fuel cell stacks (SOFC) is the need for long term stable seals at the operational temperature between 850 and 1000 deg. C. In the present work the formation and properties of sealing materials for SOFC stacks that fulfil the necessary requirements were investigated. The work comprises analysis of sealing material properties independently, in simple systems as well as tests in real SOFC stacks. The analysed sealing materials were based on pure glasses or glass-ceramic composites having B{sub 2}O{sub 3}, P{sub 2}O{sub 5} or siO{sub 2} as glass formers, and the following four glass systems were investigated: MgO/caO/Cr{sub 2}O{sub 3}-Al{sub 2}O{sub 3}B{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}, MgO-Al{sub 2}O{sub 3}-P{sub 2}O{sub 5}-SiO{sub 2} and BaO/Na{sub 2}O-Al{sub 2}O{sub 3}-SiO{sub 2}. (au) 32 tabs., 106 ills., 107 refs.

  15. Development of solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Dae Kab; Kim, Sun Jae; Jung, Choong Hwan; Kim, Kyung Hoh; Park, Ji Yun; Oh, Suk Jin [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

    1995-01-01

    Solid Oxide Fuel Cell (SOFC) technologies that use zirconium oxide as the electrolyte material were studied in this present report. SOFC exhibits a very high power generation efficiency of over 50 %, and does not discharge pollution materials such as dusts, sulfur dioxide, and nitrogen oxide. Zirconia, Ni/YSZ (yttria stabilized zirconia), and La-Sr-Mn-Oxide materials were developed for the electrolyte material, for the anode, and for the cathode, respectively. After making thin zirconia plate using tape casting process, anode and cathode powders were screen printed on the zirconia plate for fabricating unit cells. A test system composed of a vertical tube furnace, digital multimeter, DC current supplier, and measuring circuit was constructed for testing the unit cell performance. This system was controlled by a home-made computer program. Founded on this unit cell technology and system, a multi-stack SOFC system was studied. This system was composed of 10 unit cells each of them had an electrode area of 40 x 40 mm. Based on this system design, large and thin zirconia plates of 70 x 70 mm in area was fabricated for the electrolyte. Different from in the unit cell system, interconnectors are needed in the multi-stack system for connecting unit cells electrically. For this interconnectors, Inconel 750 alloy was selected, sliced into wafers, machined, surface finished, and then Pt-plated. 55 figs, 8 tabs, 51 refs. (Author).

  16. Stack configurations for tubular solid oxide fuel cells

    Science.gov (United States)

    Armstrong, Timothy R.; Trammell, Michael P.; Marasco, Joseph A.

    2010-08-31

    A fuel cell unit includes an array of solid oxide fuel cell tubes having porous metallic exterior surfaces, interior fuel cell layers, and interior surfaces, each of the tubes having at least one open end; and, at least one header in operable communication with the array of solid oxide fuel cell tubes for directing a first reactive gas into contact with the porous metallic exterior surfaces and for directing a second reactive gas into contact with the interior surfaces, the header further including at least one busbar disposed in electrical contact with at least one surface selected from the group consisting of the porous metallic exterior surfaces and the interior surfaces.

  17. Combustion of large solid fuels in cement rotary kilns

    DEFF Research Database (Denmark)

    Nielsen, Anders Rooma

    The cement industry has a significant interest in replacing fossil fuels with alternative fuels in order to minimize production costs and reduce CO2 emissions. These new alternative fuels are in particular solid fuels such as refuse derived fuel (RDF), tire-derived fuel (TDF), meat and bone meal...... fuels will be mixed into the cement raw materials, which is likely to affect process stability and clinker quality, as described above. The mixing of fuels and raw materials was studied experimentally in a pilot-scale rotary drum and was found to be a fast process, reaching steady state within few drum...... revolutions. Thus, heat transfer by conduction from the cement raw materials to the fuel particles is a major heat transfer mechanism rather than convection or radiation from the freeboard gas above the material bed. Consequently, the temperature of the cement raw materials becomes a factor of great...

  18. Technoeconomy of different solid oxide fuel cell based hybrid cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Gas turbine, steam turbine and heat engine (Stirling engine) is used as bottoming cycle for a solid oxide fuel cell plant to compare different plants efficiencies, CO2 emissionsand plants cost in terms of $/kW. Each plant is then integrated with biomass gasification and finally six plants...... configurations are compared with each other. Technoeconomy is used when calculating the cost if the plants. It is found that when a solid oxide fuel cell plant is combined with a gas turbine cycle then the plant efficiency will be the highest one while if a biomass gasification plant is integrated...... with these hybrid cycles then integrated biomass gasification with solid oxide fuel cell and steam cycle will have the highest plant efficiency. The cost of solid oxide fuel cell with steam plant is found to be the lowest one with a value of about 1030$/kW....

  19. Lowering the temperature of solid oxide fuel cells.

    Science.gov (United States)

    Wachsman, Eric D; Lee, Kang Taek

    2011-11-18

    Fuel cells are uniquely capable of overcoming combustion efficiency limitations (e.g., the Carnot cycle). However, the linking of fuel cells (an energy conversion device) and hydrogen (an energy carrier) has emphasized investment in proton-exchange membrane fuel cells as part of a larger hydrogen economy and thus relegated fuel cells to a future technology. In contrast, solid oxide fuel cells are capable of operating on conventional fuels (as well as hydrogen) today. The main issue for solid oxide fuel cells is high operating temperature (about 800°C) and the resulting materials and cost limitations and operating complexities (e.g., thermal cycling). Recent solid oxide fuel cells results have demonstrated extremely high power densities of about 2 watts per square centimeter at 650°C along with flexible fueling, thus enabling higher efficiency within the current fuel infrastructure. Newly developed, high-conductivity electrolytes and nanostructured electrode designs provide a path for further performance improvement at much lower temperatures, down to ~350°C, thus providing opportunity to transform the way we convert and store energy.

  20. Solid oxide fuel cell generator with removable modular fuel cell stack configurations

    Science.gov (United States)

    Gillett, J.E.; Dederer, J.T.; Zafred, P.R.; Collie, J.C.

    1998-04-21

    A high temperature solid oxide fuel cell generator produces electrical power from oxidation of hydrocarbon fuel gases such as natural gas, or conditioned fuel gases, such as carbon monoxide or hydrogen, with oxidant gases, such as air or oxygen. This electrochemical reaction occurs in a plurality of electrically connected solid oxide fuel cells bundled and arrayed in a unitary modular fuel cell stack disposed in a compartment in the generator container. The use of a unitary modular fuel cell stack in a generator is similar in concept to that of a removable battery. The fuel cell stack is provided in a pre-assembled self-supporting configuration where the fuel cells are mounted to a common structural base having surrounding side walls defining a chamber. Associated generator equipment may also be mounted to the fuel cell stack configuration to be integral therewith, such as a fuel and oxidant supply and distribution systems, fuel reformation systems, fuel cell support systems, combustion, exhaust and spent fuel recirculation systems, and the like. The pre-assembled self-supporting fuel cell stack arrangement allows for easier assembly, installation, maintenance, better structural support and longer life of the fuel cells contained in the fuel cell stack. 8 figs.

  1. Symmetrical, bi-electrode supported solid oxide fuel cell

    Science.gov (United States)

    Cable, Thomas L. (Inventor); Sofie, Stephen W. (Inventor)

    2009-01-01

    The present invention is a symmetrical bi-electrode supported solid oxide fuel cell comprising a sintered monolithic framework having graded pore electrode scaffolds that, upon treatment with metal solutions and heat subsequent to sintering, acquire respective anodic and cathodic catalytic activity. The invention is also a method for making such a solid oxide fuel cell. The graded pore structure of the graded pore electrode scaffolds in achieved by a novel freeze casting for YSZ tape.

  2. Combustion of solid alternative fuels in the cement kiln burner

    DEFF Research Database (Denmark)

    Nørskov, Linda Kaare

    stability, and process efficiency. Alternative fuel substitution in the calciner unit has reached close to 100% at many cement plants and to further increase the use of alternative fuels rotary kiln substitution must be enhanced. At present, limited systematic knowledge of the alternative fuel combustion...... properties and the influence on the flame formation is available. In this project a scientific approach to increase the fundamental understanding of alternative fuel conversion in the rotary kiln burner is employed through literature studies, experimental combustion characterisation studies, combustion...... modelling, data collection and observations at an industrial cement plant firing alternative fuels. Alternative fuels may differ from conventional fossil fuels in combustion behaviour through differences in physical and chemical properties and reaction kinetics. Often solid alternative fuels are available...

  3. Apparatus and method for solid fuel chemical looping combustion

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardane, Ranjani V; Weber, Justin M

    2015-04-14

    The disclosure provides an apparatus and method utilizing fuel reactor comprised of a fuel section, an oxygen carrier section, and a porous divider separating the fuel section and the oxygen carrier section. The porous divider allows fluid communication between the fuel section and the oxygen carrier section while preventing the migration of solids of a particular size. Maintaining particle segregation between the oxygen carrier section and the fuel section during solid fuel gasification and combustion processes allows gases generated in either section to participate in necessary reactions while greatly mitigating issues associated with mixture of the oxygen carrier with char or ash products. The apparatus and method may be utilized with an oxygen uncoupling oxygen carrier such as CuO, Mn.sub.3O.sub.4, or Co.sub.3O.sub.4, or utilized with a CO/H.sub.2 reducing oxygen carrier such as Fe.sub.2O.sub.3.

  4. Yttria-stabilized zirconia solid oxide electrolyte fuel cells: Monolithic solid oxide fuel cells

    Science.gov (United States)

    1990-10-01

    The monolithic solid oxide fuel cell (MSOFC) is currently under development for a variety of applications including coal-based power generation. The MSOFC is a design concept that places the thin components of a solid oxide fuel cell in lightweight, compact, corrugated structure, and so achieves high efficiency and excellent performance simultaneously with high power density. The MSOFC can be integrated with coal gasification plants and is expected to have high overall efficiency in the conversion of the chemical energy of coal to electrical energy. This report describes work aimed at: (1) assessing manufacturing costs for the MSOFC and system costs for a coal-based plant; (2) modifying electrodes and electrode/electrolyte interfaces to improve the electrochemical performance of the MSOFC; and (3) testing the performance of the MSOFC on hydrogen and simulated coal gas. Manufacturing costs for both the coflow and crossflow MSOFC's were assessed based on the fabrication flow charts developed by direct scaleup of tape calendering and other laboratory processes. Integrated coal-based MSOFC systems were investigated to determine capital costs and costs of electricity. Design criteria were established for a coal-fueled 200-Mw power plant. Four plant arrangements were evaluated, and plant performance was analyzed. Interfacial modification involved modification of electrodes and electrode/electrolyte interfaces to improve the MSOFC electrochemical performance. Work in the cathode and cathode/electrolyte interface was concentrated on modification of electrode porosity, electrode morphology, electrode material, and interfacial bonding. Modifications of the anode and anode/electrolyte interface included the use of additives and improvement of nickel distribution. Single cells have been tested for their electrochemical performance. Performance data were typically obtained with humidified H2 or simulated coal gas and air or oxygen.

  5. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2017-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s...

  6. Direct Coal Oxidation in Modified Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Gil, Vanesa; Ippolito, Davide

    2015-01-01

    Hybrid direct carbon fuel cells employ a classical solid oxide fuel cell together with carbon dispersed in a carbonate melt on the anode side. In a European project, the utilization of various coals has been investigated with and without addition of an oxidation catalyst to the carbon-carbonate s...

  7. Theory of flame spread above solids. [fuel exothermic surface reactions

    Science.gov (United States)

    Sirignano, W. A.

    1974-01-01

    A theory for flame spread above a solid fuel is presented. The special case is considered whereby the oxidation is an exothermic surface reaction. The spreading rate is predicted as a function of the thermochemical properties, fuel-bed thickness, and convective velocity. Also, the theory predicts temperature, mass fraction, and heat flux as a function of position.

  8. Sulfur Release from Cement Raw Materials during Solid Fuel Combustion

    DEFF Research Database (Denmark)

    Nielsen, Anders Rooma; Larsen, Morten B.; Glarborg, Peter

    2011-01-01

    During combustion of solid fuels in the material inlet end of cement rotary kilns, local reducing conditions can occur and cause decomposition of sulfates from cement raw materials. Decomposition of sulfates is problematic because it increases the gas-phase SO2 concentration, which may cause...... deposit formation in the kiln system. SO2 release from cement raw materials during combustion of solid fuels has been studied experimentally in a high temperature rotary drum. The fuels were tire rubber, pine wood, petcoke, sewage sludge, and polypropylene. The SO2 release from the raw materials...

  9. Solid Oxide Fuel Cell Stack Diagnostics

    DEFF Research Database (Denmark)

    Mosbæk, Rasmus Rode; Barfod, Rasmus Gottrup

    . An operating stack is subject to compositional gradients in the gaseous reactant streams, and temperature gradients across each cell and across the stack, which complicates detailed analysis. Several experimental stacks from Topsoe Fuel Cell A/S were characterized using Electrochemical Impedance Spectroscopy...... and discussed in the following. Parallel acquisition using electrochemical impedance spectroscopy can be used to detect possible minor differences in the supply of gas to the individual cells, which is important when going to high fuel utilizations. The fuel flow distribution was determined and provides...... carried out on an experimental 14-cell SOFC stack at varying frequencies and fuel utilizations. The results illustrated that THD can be used to detect increasing non-linearities in the current-voltage characteristics of the stack when the stack suffers from fuel starvation by monitoring the stack sum...

  10. Thin-film solid-oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Jankowski, A.F.

    1997-05-01

    Fuel cells are energy conversion devices that would save billions of dollars in fuel costs alone each year in the United States if they could be implemented today for stationary and transportation applications (1-5). There are a wide variety of fuel cells available, e.g. molten carbonate, phosphoric acid, proton exchange membrane and solid-oxide. However, solid-oxide fuel cells (SOFCS) are potentially more efficient and less expensive per kilowatt of power in comparison to other fuel cells. For transportation applications, the energy efficiency of a conventional internal combustion engine would be increased two-fold as replaced with a zero-emission SOFC. The basic unit of a SOFC consists of an anode and cathode separated by an oxygen-ion conducting, electrolyte layer. Manifolded stacks of fuel cells, with electrical interconnects, enable the transport and combination of a fuel and oxidant at elevated temperature to generate electrical current. Fuel cell development has proceeded along different paths based on the configuration of the anode-electrolyte-cathode. Various configurations include the tubular, monolithic and planar geometries. A planar geometry for the anode-electrolyte-cathode accompanied by a reduction in layer thickness offers the potential for high power density. Maximum power densities will require yet additional innovations in the assembly of fuel cell stacks with all of the manifolding stipulations for gas flow and electrical interconnects.

  11. Redox Stable Anodes for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Guoliang eXiao

    2014-06-01

    Full Text Available Solid oxide fuel cells (SOFCs can convert chemical energy from the fuel directly to electrical energy with high efficiency and fuel flexibility. Ni-based cermets have been the most widely adopted anode for SOFCs. However, the conventional Ni-based anode has low tolerance to sulfur-contamination, is vulnerable to deactivation by carbon build-up (coking from direct oxidation of hydrocarbon fuels, and suffers volume instability upon redox cycling. Among these limitations, the redox instability of the anode is particularly important and has been intensively studied since the SOFC anode may experience redox cycling during fuel cell operations even with the ideal pure hydrogen as the fuel. This review aims to highlight recent progresses on improving redox stability of the conventional Ni-based anode through microstructure optimization and exploration of alternative ceramic-based anode materials.

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

    Science.gov (United States)

    Ruka, Roswell J.; Vora, Shailesh D.

    2001-01-01

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

  13. Pressurized solid oxide fuel cell testing

    Energy Technology Data Exchange (ETDEWEB)

    Basel, R.A.; Pierre, J.F.

    1995-08-01

    The goals of the SOFC pressurized test program are to obtain cell voltage versus current (VI) performance data as a function of pressure; to evaluate the effects of operating parameters such as temperature, air stoichiometry, and fuel utilization on cell performance, and to demonstrate long term stability of the SOFC materials at elevated pressures.

  14. Integration of a municipal solid waste gasification plant with solid oxide fuel cell and gas turbine

    DEFF Research Database (Denmark)

    Bellomare, Filippo; Rokni, Masoud

    2013-01-01

    in landfills. A Municipal Solid Waste Gasification Plant Integrated with Solid Oxide Fuel Cell (SOFC) and Gas Turbine (GT) has been studied and the plant is called IGSG (Integrated Gasification SOFC and GT). Gasification plant is fed by MSW to produce syngas by which the anode side of an SOFC is fed wherein...

  15. Bioenergy in Germany. Facts and figures. Solid fuels, biofuels, biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-04-11

    The brochure under consideration gives statistical information about the bioenergy in Germany: Renewable energies (bioenergy) and solid fuels. For example, the structure of the primary energy consumption in the year 2010, the energy supply from renewables, gross electricity generation, the total sales of renewables, growth in number of installed pellet boilers, wood fuel equivalent prices by energy value or biofuels in comparison with heating oil are presented.

  16. Coatings on stainless steel for solid oxide fuel cell interconnects

    OpenAIRE

    Clarke, Richard

    2012-01-01

    Enabling inexpensive and ubiquitous steels for use as solid oxide fuel cell interconnects has two major hurdles to overcome. Firstly, corrosion must be limited such that the interconnect can have longevity. Secondly, the evaporation of chromium from the corrosion layer must also be limited such that the fuel cell can have longevity. The evaporation of chromium from chromia, titanium doped chromia, and chromium cobalt spinels was studied and characterized. Spinels lost the least amount of m...

  17. Five Kilowatt Solid Oxide Fuel Cell/Diesel Reformer

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Witmer; Thomas Johnson

    2008-12-31

    Reducing fossil fuel consumption both for energy security and for reduction in global greenhouse emissions has been a major goal of energy research in the US for many years. Fuel cells have been proposed as a technology that can address both these issues--as devices that convert the energy of a fuel directly into electrical energy, they offer low emissions and high efficiencies. These advantages are of particular interest to remote power users, where grid connected power is unavailable, and most electrical power comes from diesel electric generators. Diesel fuel is the fuel of choice because it can be easily transported and stored in quantities large enough to supply energy for small communities for extended periods of time. This projected aimed to demonstrate the operation of a solid oxide fuel cell on diesel fuel, and to measure the resulting efficiency. Results from this project have been somewhat encouraging, with a laboratory breadboard integration of a small scale diesel reformer and a Solid Oxide Fuel Cell demonstrated in the first 18 months of the project. This initial demonstration was conducted at INEEL in the spring of 2005 using a small scale diesel reformer provided by SOFCo and a fuel cell provided by Acumentrics. However, attempts to integrate and automate the available technology have not proved successful as yet. This is due both to the lack of movement on the fuel processing side as well as the rather poor stack lifetimes exhibited by the fuel cells. Commercial product is still unavailable, and precommercial devices are both extremely expensive and require extensive field support.

  18. Solid oxide fuel cell steam reforming power system

    Science.gov (United States)

    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%.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh; Jim Powers

    2003-10-01

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

  20. The utilisation of solid wastes as solid fuel in some EU-countries

    Energy Technology Data Exchange (ETDEWEB)

    E. Erdin; A. Urut; G. Sen; A. Alten [Dokuz Eylul University, Izmir (Turkey). Faculty of Engineering, Environmental Engineering Department

    2003-07-01

    According to regulation 2000/7/EG, the paper explores whether solid wastes (SW) should be used as additional fuel with conventional fuels for production and also in solid waste combustion plants. The allowable limit to combust hazardous wastes is 40% maximum. But domestic wastes should contribute at higher percentages. Every EU-member state must adopt this regulation to its national regulations till 28.12.2002. This paper summarizes the research into utilization of solid waste as an additive fuel to coal in the cement industry and describes the Gavi-van and Duesseldorf plants for combustion of municipal solid wastes. It outlines the Asslar-Wetzlar dry bio-stabilization technology which is being used to produce compost in Turkey. 7 refs., 1 fig., 6 tabs.

  1. LG Solid Oxide Fuel Cell (SOFC) Model Development

    Energy Technology Data Exchange (ETDEWEB)

    Haberman, Ben [LG Fuel Cell Systems Inc., North Canton, OH (United States); Martinez-Baca, Carlos [LG Fuel Cell Systems Inc., North Canton, OH (United States); Rush, Greg [LG Fuel Cell Systems Inc., North Canton, OH (United States)

    2013-05-31

    This report presents a summary of the work performed by LG Fuel Cell Systems Inc. during the project LG Solid Oxide Fuel Cell (SOFC) Model Development (DOE Award Number: DE-FE0000773) which commenced on October 1, 2009 and was completed on March 31, 2013. The aim of this project is for LG Fuel Cell Systems Inc. (formerly known as Rolls-Royce Fuel Cell Systems (US) Inc.) (LGFCS) to develop a multi-physics solid oxide fuel cell (SOFC) computer code (MPC) for performance calculations of the LGFCS fuel cell structure to support fuel cell product design and development. A summary of the initial stages of the project is provided which describes the MPC requirements that were developed and the selection of a candidate code, STAR-CCM+ (CD-adapco). This is followed by a detailed description of the subsequent work program including code enhancement and model verification and validation activities. Details of the code enhancements that were implemented to facilitate MPC SOFC simulations are provided along with a description of the models that were built using the MPC and validated against experimental data. The modeling work described in this report represents a level of calculation detail that has not been previously available within LGFCS.

  2. The combustion of solid fuels and wastes

    CERN Document Server

    Tillman, David

    1991-01-01

    Careful organization and empirical correlations help clarify the prodigious technical information presented in this useful reference.Key Features* Written for practicing engineers, this comprehensive book supplies an overall framework of the combustion process; It connects information on specific reactions and reaction sequences with current applications and hardware; Each major group of combustion solids is evaluated; Among the many topics covered are:* Various biomass forms* The coalification process* Grate, kiln, and suspension firing* Fluidized bed combustion

  3. Conversion of hydrocarbons in solid oxide fuel cells

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Kammer Hansen, K.

    2003-01-01

    Recently, a number of papers about direct oxidation of methane and hydrocarbon in solid oxide fuel cells (SOFC) at relatively low temperatures (about 700degreesC) have been published. Even though the conversion of almost dry CH4 at 1000degreesC on ceramic anodes was demonstrated more than 10 years...

  4. Determination of moisture and low temperature volatiles in solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    Jenke, D.R.; Hannifan, M.R.

    1983-09-01

    The reaction of calcium carbide with moisture in a closed reactor to form acetylene, when combined with gas chromatographic analysis of the products and measurement of pressure change during reaction, provides an accurate and rapid determination method for moisture and volatile content of solid fuels.

  5. Viscous sealing glass compositions for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Cheol Woon; Brow, Richard K.

    2016-12-27

    A sealant for forming a seal between at least two solid oxide fuel cell components wherein the sealant comprises a glass material comprising B.sub.2O.sub.3 as a principal glass former, BaO, and other components and wherein the glass material is substantially alkali-free and contains less than 30% crystalline material.

  6. Production of Solid Fuel Briquettes from Agricultural and Wood ...

    African Journals Online (AJOL)

    Fibrous agricultural and wood waste materials have been compressed with suitable adhesive into solid fuel briquettes in a compressing machine, which was designed and constructed for this purpose. Nine samples of fibrous waste materials were prepared into different categories:- Category A (100% saw-dust, 100% ...

  7. Modeling and Structural Optimization of Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Panagakos, Grigorios

    the setup as continuum) and we combine these scripts with the ones containing the optimization routines like the Method of Moving Asymptotes (MMA). Success in obtaining such a design, would greatly affect the overall cell's efficiency rendering the Solid Oxide Fuel Cell more competitive in the sustainable...

  8. Impedance Modeling of Solid Oxide Fuel Cell Cathodes

    DEFF Research Database (Denmark)

    Mortensen, Jakob Egeberg; Søgaard, Martin; Jacobsen, Torben

    2010-01-01

    A 1-dimensional impedance model for a solid oxide fuel cell cathode is formulated and applied to a cathode consisting of 50/50 wt% strontium doped lanthanum cobaltite and gadolinia doped ceria. A total of 42 impedance spectra were recorded in the temperature range: 555-852°C and in the oxygen...

  9. pollution from household use of solid fuels in South Africa

    African Journals Online (AJOL)

    Objectives. To estimate the burden of respiratory ill health in. South African children and adults in 2000 from exposure to indoor air pollution associated with household use of solid fuels. Design. World Health Organization comparative risk assessment. (CRA) methodology was followed. The South African Census. 2001 was ...

  10. Trends for Methane Oxidation at Solid Oxide Fuel Cell Conditions

    DEFF Research Database (Denmark)

    Kleis, Jesper; Jones, Glenn; Abild-Pedersen, Frank

    2009-01-01

    First-principles calculations are used to predict a plausible reaction pathway for the methane oxidation reaction. In turn, this pathway is used to obtain trends in methane oxidation activity at solid oxide fuel cell (SOFC) anode materials. Reaction energetics and barriers for the elementary...

  11. Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Faress Rahman; Nguyen Minh

    2004-01-04

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC (HPGS) during the July 2003 to December 2003 reporting period under Cooperative Agreement DE-FC26-01NT40779 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Solid Oxide Fuel Cell Hybrid System for Distributed Power Generation''. The main objective of this project is to develop and demonstrate the feasibility of a highly efficient hybrid system integrating a planar Solid Oxide Fuel Cell (SOFC) and a micro-turbine. In addition, an activity included in this program focuses on the development of an integrated coal gasification fuel cell system concept based on planar SOFC technology. Also, another activity included in this program focuses on the development of SOFC scale up strategies.

  12. Solid Hydrogen Particles Analyzed for Atomic Fuels

    Science.gov (United States)

    Palaszewski, Bryan A.

    2001-01-01

    Solid hydrogen particles have been selected as a means of storing atomic propellants in future launch vehicles (refs. 1 to 2). In preparation for this, hydrogen particle formation in liquid helium was tested experimentally. These experiments were conducted to visually characterize the particles and to observe their formation and molecular transformations (aging) while in liquid helium. The particle sizes, molecular transformations, and agglomeration times were estimated from video image analyses. The experiments were conducted at the NASA Glenn Research Center in the Supplemental Multilayer Insulation Research Facility (SMIRF, ref. 3). The facility has a vacuum tank, into which the experimental setup was placed. The vacuum tank prevented heat leaks and subsequent boiloff of the liquid helium, and the supporting systems maintained the temperature and pressure of the liquid helium bath where the solid particles were created. As the operation of the apparatus was developed, the hydrogen particles were easily visualized. The figures (ref. 1) show images from the experimental runs. The first image shows the initial particle freezing, and the second image shows the particles after the small particles have agglomerated. The particles finally all clump, but stick together loosely. The solid particles tended to agglomerate within a maximum of 11 min, and the agglomerate was very weak. Because the hydrogen particles are buoyant in the helium, the agglomerate tends to compact itself into a flat pancake on the surface of the helium. This pancake agglomerate is easily broken apart by reducing the pressure above the liquid. The weak agglomerate implies that the particles can be used as a gelling agent for the liquid helium, as well as a storage medium for atomic boron, carbon, or hydrogen. The smallest particle sizes that resulted from the initial freezing experiments were about 1.8 mm. About 50 percent of the particles formed were between 1.8 to 4.6 mm in diameter. These very

  13. Chemical analysis of solid residue from liquid and solid fuel combustion: Method development and validation

    Energy Technology Data Exchange (ETDEWEB)

    Trkmic, M. [University of Zagreb, Faculty of Mechanical Engineering and Naval Architecturek Zagreb (Croatia); Curkovic, L. [University of Zagreb, Faculty of Chemical Engineering and Technology, Zagreb (Croatia); Asperger, D. [HEP-Proizvodnja, Thermal Power Plant Department, Zagreb (Croatia)

    2012-06-15

    This paper deals with the development and validation of methods for identifying the composition of solid residue after liquid and solid fuel combustion in thermal power plant furnaces. The methods were developed for energy dispersive X-ray fluorescence (EDXRF) spectrometer analysis. Due to the fuels used, the different composition and the location of creation of solid residue, it was necessary to develop two methods. The first method is used for identifying solid residue composition after fuel oil combustion (Method 1), while the second method is used for identifying solid residue composition after the combustion of solid fuels, i. e. coal (Method 2). Method calibration was performed on sets of 12 (Method 1) and 6 (Method 2) certified reference materials (CRM). CRMs and analysis test samples were prepared in pellet form using hydraulic press. For the purpose of method validation the linearity, accuracy, precision and specificity were determined, and the measurement uncertainty of methods for each analyte separately was assessed. The methods were applied in the analysis of real furnace residue samples. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Agglomeration and Deposition Behaviour of Solid Recovered Fuel

    DEFF Research Database (Denmark)

    Pedersen, Morten Nedergaard; Jensen, Peter Arendt; Hjuler, Klaus

    2016-01-01

    Waste-derived fuels, such as solid recovered fuel (SRF), are increasingly being used in, e.g., the cement industry as a means to reduce cost. The inhomogeneous nature of SRF makes it difficult to combust, and many problems may arise within, e.g., combustion control, feeding of fuel, deposit...... formation, or accumulation of impurities. The combustion of polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), wood, and SRF were studied in a rotary drum furnace. The combustion was recorded on a camera (60 frames per second), so that any agglomeration or deposition of fuel or ash...... could be monitored. PE and PP pose no significant risk of forming deposits in a combustion environment (T > 800 °C) as a result of a rapid devolatilization, while PET may cause deposits as a result of a sticky char residue. The deposition tendency of the investigated SRF is low, and it may be managed...

  15. Status of solid polymer fuel cell system development

    Science.gov (United States)

    Shoesmith, J. P.; Collins, R. D.; Oakley, M. J.; Stevenson, D. K.

    1994-04-01

    Solid polymer fuel cell (SPFC) systems are expected to see service in a wide variety of applications, including road vehicles, trains, ships, undersea power, and small scale stationary power generation. Each application brings unique requirements in terms of fuel, power, efficiency, volume and weight and, consequently, SPFC systems are expected to take a variety of forms. This paper reviews the development issues which must be resolved before SPFC systems can enter commercial service. It includes the results of system studies completed by Rolls-Royce and Associates during the last two years. Development priorities are highlighted, particularly for the stack and fuel processing system. Results of the testing of a novel compact fuel processing system are presented.

  16. Nondestructive characterization methods for monolithic solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ellingson, W.A.

    1993-01-01

    Monolithic solid oxide fuel cells (MSOFCS) represent a potential breakthrough in fuel cell technology, provided that reliable fabrication methods can be developed. Fabrication difficulties arise in several steps of the processing: First is the fabrication of uniform thin (305 {mu}m) single-layer and trilayer green tapes (the trilayer tapes of anode/electrolyte/cathode and anode/interconnect/cathode must have similar coefficients of thermal expansion to sinter uniformly and to have the necessary electrochemical properties); Second is the development of fuel and oxidant channels in which residual stresses are likely to develop in the tapes; Third is the fabrication of a ``complete`` cell for which the bond quality between layers and the quality of the trilayers must be established; and Last, attachment of fuel and oxidant manifolds and verification of seal integrity. Purpose of this report is to assess nondestructive characterization methods that could be developed for application to laboratory, prototype, and full-scale MSOFCs.

  17. Solid Hydrogen Particles and Flow Rates Analyzed for Atomic Fuels

    Science.gov (United States)

    Palaszewski, Bryan A.

    2003-01-01

    The experiments were conducted at Glenn's Small Multipurpose Research Facility (SMIRF, ref. 5). The experimental setup was placed in the facility's vacuum tank to prevent heat leaks and subsequent boiloff of the liquid helium. Supporting systems maintained the temperature and pressure of the liquid helium bath where the solid particles were created. Solid hydrogen particle formation was tested from February 23 to April 2, 2001. Millimeter-sized solid-hydrogen particles were formed in a Dewar of liquid helium as a prelude to creating atomic fuels and propellants for aerospace vehicles. Atomic fuels or propellants are created when atomic boron, carbon, or hydrogen is stored in solid hydrogen particles. The current testing characterized the solid hydrogen particles without the atomic species, as a first step to creating a feed system for the atomic fuels and propellants. This testing did not create atomic species, but only sought to understand the solid hydrogen particle formation and behavior in the liquid helium. In these tests, video images of the solid particle formation were recorded, and the total mass flow rate of the hydrogen was measured. The mass of hydrogen that went into the gaseous phase was also recorded using a commercially available residual gas analyzer. The temperatures, pressures, and flow rates of the liquids and gases in the test apparatus were recorded as well. Testing conducted in 1999 recorded particles as small as 2 to 5 mm in diameter. The current testing extended the testing conditions to a very cold Dewar ullage gas of about 20 to 90 K above the 4 K liquid helium. With the very cold Dewar gas, the hydrogen freezing process took on new dimensions, in some cases creating particles so small that they seemed to be microscopic, appearing as infinitesimally small scintillations on the videotaped images.

  18. PRODUCTION OF NEW BIOMASS/WASTE-CONTAINING SOLID FUELS

    Energy Technology Data Exchange (ETDEWEB)

    David J. Akers; Glenn A. Shirey; Zalman Zitron; Charles Q. Maney

    2001-04-20

    CQ Inc. and its team members (ALSTOM Power Inc., Bliss Industries, McFadden Machine Company, and industry advisors from coal-burning utilities, equipment manufacturers, and the pellet fuels industry) addressed the objectives of the Department of Energy and industry to produce economical, new solid fuels from coal, biomass, and waste materials that reduce emissions from coal-fired boilers. This project builds on the team's commercial experience in composite fuels for energy production. The electric utility industry is interested in the use of biomass and wastes as fuel to reduce both emissions and fuel costs. In addition to these benefits, utilities also recognize the business advantage of consuming the waste byproducts of customers both to retain customers and to improve the public image of the industry. Unfortunately, biomass and waste byproducts can be troublesome fuels because of low bulk density, high moisture content, variable composition, handling and feeding problems, and inadequate information about combustion and emissions characteristics. Current methods of co-firing biomass and wastes either use a separate fuel receiving, storage, and boiler feed system, or mass burn the biomass by simply mixing it with coal on the storage pile. For biomass or biomass-containing composite fuels to be extensively used in the U.S., especially in the steam market, a lower cost method of producing these fuels must be developed that includes both moisture reduction and pelletization or agglomeration for necessary fuel density and ease of handling. Further, this method of fuel production must be applicable to a variety of combinations of biomass, wastes, and coal; economically competitive with current fuels; and provide environmental benefits compared with coal. Notable accomplishments from the work performed in Phase I of this project include the development of three standard fuel formulations from mixtures of coal fines, biomass, and waste materials that can be used in

  19. Solid Oxide Fuel Cells coupled with a biomass gasification unit

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available A possibility of fuelling a solid oxide fuel cell stack (SOFC with biomass fuels can be realized by coupling a SOFC system with a self-standing gasification unit. Such a solution enables multi-fuel operation, elasticity of the system as well as the increase of the efficiency of small-scale biomass-to-electricity conversion units. A system of this type, consisting of biomass gasification unit, gas purification unit, SOFC stack, anode off-gas afterburner and peripherals was constructed and operated successfully. During the process, biomass fuel (wood chips was gasified with air as gasification agent. The gasifier was capable of converting up to 30 kW of fuel to syngas with efficiencies up to 75%. Syngas leaving the gasification unit is delivered to a medium temperature adsorber for sulphur compounds removal. Steam is added to the purified fuel to maintain steam to carbon ratio higher than 2. The syngas then is passed to a SOFC stack through a fuel preheater. In such a configuration it was possible to operate a commercial 1.3 kW stack within its working regime. Conducted tests confirmed successful operation of a SOFC stack fuelled by biomass-sourced syngas.

  20. Carbon as a fuel for efficient electricity generation in carbon solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Skrzypkiewicz Marek

    2016-01-01

    Full Text Available In this paper, the impact of the physicochemical properties of carbonaceous solid fuels on the performance of a direct carbon solid oxide fuel cell (DC-SOFC was investigated. High-purity synthetic carbon powders such as carbon black N-220 and Carbo Medicinalis FP5 were chosen for analytical and electrochemical investigations in a DC-SOFC. The research focussed on choosing an optimised, cost-effective, high-purity carbon powder which could be applied as a solid reference fuel for all tests performed on a single DC-SOFC cell as well as on DC-SOFC stack constructions. Most of the electrochemical investigations described in this paper were performed using square DCSOFCs with dimensions of 5 × 5 cm. The relationship between structure, physicochemical properties, and electrochemical reactivity in a DC-SOFC was analysed.

  1. A novel direct carbon fuel cell by approach of tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Renzhu; Zhao, Chunhua; Li, Junliang; Zeng, Fanrong; Wang, Shaorong; Wen, Tinglian; Wen, Zhaoyin [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Inorganic Energy Materials and Power Source Engineering Center, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

    2010-01-15

    A direct carbon fuel cell based on a conventional anode-supported tubular solid oxide fuel cell, which consisted of a NiO-YSZ anode support tube, a NiO-ScSZ anode functional layer, a ScSZ electrolyte film, and a LSM-ScSZ cathode, has been successfully achieved. It used the carbon black as fuel and oxygen as the oxidant, and a preliminary examination of the DCFC has been carried out. The cell generated an acceptable performance with the maximum power densities of 104, 75, and 47 mW cm{sup -2} at 850, 800, and 750 C, respectively. These results demonstrate the feasibility for carbon directly converting to electricity in tubular solid oxide fuel cells. (author)

  2. Santa Clara County Planar Solid Oxide Fuel Cell Demonstration Project

    Energy Technology Data Exchange (ETDEWEB)

    Fred Mitlitsky; Sara Mulhauser; David Chien; Deepak Shukla; David Weingaertner

    2009-11-14

    The Santa Clara County Planar Solid Oxide Fuel Cell (PSOFC) project demonstrated the technical viability of pre-commercial PSOFC technology at the County 911 Communications headquarters, as well as the input fuel flexibility of the PSOFC. PSOFC operation was demonstrated on natural gas and denatured ethanol. The Santa Clara County Planar Solid Oxide Fuel Cell (PSOFC) project goals were to acquire, site, and demonstrate the technical viability of a pre-commercial PSOFC technology at the County 911 Communications headquarters. Additional goals included educating local permit approval authorities, and other governmental entities about PSOFC technology, existing fuel cell standards and specific code requirements. The project demonstrated the Bloom Energy (BE) PSOFC technology in grid parallel mode, delivering a minimum 15 kW over 8760 operational hours. The PSOFC system demonstrated greater than 81% electricity availability and 41% electrical efficiency (LHV net AC), providing reliable, stable power to a critical, sensitive 911 communications system that serves geographical boundaries of the entire Santa Clara County. The project also demonstrated input fuel flexibility. BE developed and demonstrated the capability to run its prototype PSOFC system on ethanol. BE designed the hardware necessary to deliver ethanol into its existing PSOFC system. Operational parameters were determined for running the system on ethanol, natural gas (NG), and a combination of both. Required modeling was performed to determine viable operational regimes and regimes where coking could occur.

  3. Pollutants generated by the combustion of solid biomass fuels

    CERN Document Server

    Jones, Jenny M; Ma, Lin; Williams, Alan; Pourkashanian, Mohamed

    2014-01-01

    This book considers the pollutants formed by the combustion of solid biomass fuels. The availability and potential use of solid biofuels is first discussed because this is the key to the development of biomass as a source of energy.This is followed by details of the methods used for characterisation of biomass and their classification.The various steps in the combustion mechanisms are given together with a compilation of the kinetic data. The chemical mechanisms for the formation of the pollutants: NOx, smoke and unburned hydrocarbons, SOx, Cl compounds, and particulate metal aerosols

  4. Mass, energy and material balances of SRF production process. Part 3: solid recovered fuel produced from municipal solid waste.

    Science.gov (United States)

    Nasrullah, Muhammad; Vainikka, Pasi; Hannula, Janne; Hurme, Markku; Kärki, Janne

    2015-02-01

    This is the third and final part of the three-part article written to describe the mass, energy and material balances of the solid recovered fuel production process produced from various types of waste streams through mechanical treatment. This article focused the production of solid recovered fuel from municipal solid waste. The stream of municipal solid waste used here as an input waste material to produce solid recovered fuel is energy waste collected from households of municipality. This article presents the mass, energy and material balances of the solid recovered fuel production process. These balances are based on the proximate as well as the ultimate analysis and the composition determination of various streams of material produced in a solid recovered fuel production plant. All the process streams are sampled and treated according to CEN standard methods for solid recovered fuel. The results of the mass balance of the solid recovered fuel production process showed that 72% of the input waste material was recovered in the form of solid recovered fuel; 2.6% as ferrous metal, 0.4% as non-ferrous metal, 11% was sorted as rejects material, 12% as fine faction and 2% as heavy fraction. The energy balance of the solid recovered fuel production process showed that 86% of the total input energy content of input waste material was recovered in the form of solid recovered fuel. The remaining percentage (14%) of the input energy was split into the streams of reject material, fine fraction and heavy fraction. The material balances of this process showed that mass fraction of paper and cardboard, plastic (soft) and wood recovered in the solid recovered fuel stream was 88%, 85% and 90%, respectively, of their input mass. A high mass fraction of rubber material, plastic (PVC-plastic) and inert (stone/rock and glass particles) was found in the reject material stream. © The Author(s) 2014.

  5. Planar solid oxide fuel cell with staged indirect-internal air and fuel preheating and reformation

    Science.gov (United States)

    Geisbrecht, Rodney A; Williams, Mark C

    2003-10-21

    A solid oxide fuel cell arrangement and method of use that provides internal preheating of both fuel and air in order to maintain the optimum operating temperature for the production of energy. The internal preheat passes are created by the addition of two plates, one on either side of the bipolar plate, such that these plates create additional passes through the fuel cell. This internal preheat fuel cell configuration and method reduce the requirements for external heat exchanger units and air compressors. Air or fuel may be added to the fuel cell as required to maintain the optimum operating temperature through a cathode control valve or an anode control valve, respectively. A control loop comprises a temperature sensing means within the preheat air and fuel passes, a means to compare the measured temperature to a set point temperature and a determination based on the comparison as to whether the control valves should allow additional air or fuel into the preheat or bypass manifolds of the fuel cell.

  6. Method to fabricate high performance tubular solid oxide fuel cells

    Science.gov (United States)

    Chen, Fanglin; Yang, Chenghao; Jin, Chao

    2013-06-18

    In accordance with the present disclosure, a method for fabricating a solid oxide fuel cell is described. The method includes forming an asymmetric porous ceramic tube by using a phase inversion process. The method further includes forming an asymmetric porous ceramic layer on a surface of the asymmetric porous ceramic tube by using a phase inversion process. The tube is co-sintered to form a structure having a first porous layer, a second porous layer, and a dense layer positioned therebetween.

  7. Current status of Westinghouse tubular solid oxide fuel cell program

    Energy Technology Data Exchange (ETDEWEB)

    Parker, W.G. [Westinghouse Science and Technology Center, Pittsburgh, PA (United States)

    1996-04-01

    In the last ten years the solid oxide fuel cell (SOFC) development program at Westinghouse has evolved from a focus on basic material science to the engineering of fully integrated electric power systems. Our endurance for this cell is 5 to 10 years. To date we have successfully operated at power for over six years. For power plants it is our goal to have operated before the end of this decade a MW class power plant. Progress toward these goals is described.

  8. 40 kW Stirling engine for solid fuel

    DEFF Research Database (Denmark)

    Carlsen, Henrik; Trærup, Jens; Ammundsen, Niels

    1996-01-01

    The external combustion in a Stirling engine makes it very attractive for utilisation of solid fuels in decentralised combined heat and power (CHP) plants. Only a few projects have concentrated on the development of Stirling engines specifically for biomass. In this project, a Stirling engine has...... been designed primarily for utilisation of wood chips. Maximum shaft power is 40 kW corresponding to an electric output of 36 kW. Biomass needs more space in the combustion chamber compared to gas and liquid fuels, and a large heat transfer area is necessary. The design of the new Stirling engine has...... been adapted to the special demands of combustion of wood chips, resulting in a large engine compared to engines for gas or liquid fuels. The engine has four-cylinders arranged in a square. The design is made as a hermetic unit, where the alternator is built into the pressurised crankcase so...

  9. Ultra-thin solid oxide fuel cells: Materials and devices

    Science.gov (United States)

    Kerman, Kian

    Solid oxide fuel cells are electrochemical energy conversion devices utilizing solid electrolytes transporting O2- that typically operate in the 800 -- 1000 °C temperature range due to the large activation barrier for ionic transport. Reducing electrolyte thickness or increasing ionic conductivity can enable lower temperature operation for both stationary and portable applications. This thesis is focused on the fabrication of free standing ultrathin (machining processes, respectively. Fuel cell devices integrating these membranes with metallic electrodes are demonstrated to operate in the 300 -- 500 °C range, exhibiting record performance at such temperatures. A model combining physical transport of electronic carriers in an insulating film and electrochemical aspects of transport is developed to determine the limits of performance enhancement expected via electrolyte thickness reduction. Free standing oxide heterostructures, i.e. electrolyte membrane and oxide electrodes, are demonstrated. Lastly, using Y2O3-doped ZrO2 and Gd2O 3-doped CeO2, novel electrolyte fabrication schemes are explored to develop oxide alloys and nanoscale compositionally graded membranes that are thermomechanically robust and provide added interfacial functionality. The work in this thesis advances experimental state-of-the-art with respect to solid oxide fuel cell operation temperature, provides fundamental boundaries expected for ultrathin electrolytes, develops the ability to integrate highly dissimilar material (such as oxide-polymer) heterostructures, and introduces nanoscale compositionally graded electrolyte membranes that can lead to monolithic materials having multiple functionalities.

  10. Solid Polymer Fuel Cells. Electrode and membrane performance studies

    Energy Technology Data Exchange (ETDEWEB)

    Moeller-Holst, S.

    1996-12-31

    This doctoral thesis studies aspects of fuel cell preparation and performance. The emphasis is placed on preparation and analysis of low platinum-loading solid polymer fuel cell (SPEC) electrodes. A test station was built and used to test cells within a wide range of real operating conditions, 40-150{sup o}C and 1-10 bar. Preparation and assembling equipment for single SPFCs was designed and built, and a new technique of spraying the catalyst layer directly onto the membrane was successfully demonstrated. Low Pt-loading electrodes (0.1 mg Pt/cm{sup 2}) prepared by the new technique exhibited high degree of catalyst utilization. The performance of single cells holding these electrodes is comparable to state-of-the-art SPFCs. Potential losses in single cell performance are ascribed to irreversibilities by analysing the efficiency of the Solid Oxide Fuel Cell by means of the second law of thermodynamics. The water management in membranes is discussed for a model system and the results are relevant to fuel cell preparation and performance. The new spray deposition technique should be commercially interesting as it involves few steps as well as techniques that are adequate for larger scale production. 115 refs., 43 figs., 18 tabs.

  11. Artificial neural networks application for solid fuel slagging intensity predictions

    Directory of Open Access Journals (Sweden)

    Kakietek Sławomir

    2017-01-01

    Full Text Available Slagging issues present in pulverized steam boilers very often lead to heat transfer problems, corrosion and not planned outages of boilers which increase the cost of energy production and decrease the efficiency of energy production. Slagging especially occurs in regions with reductive atmospheres which nowadays are very common due to very strict limitations in NOx emissions. Moreover alternative fuels like biomass which are also used in combustion systems from two decades in order to decrease CO2 emissions also usually increase the risk of slagging. Thus the prediction of slagging properties of fuels is not the minor issue which can be neglected before purchasing or mixing of fuels. This however is rather difficult to estimate and even commonly known standard laboratory methods like fusion temperature determination or special indexers calculated on the basis of proximate and ultimate analyses, very often have no reasonable correlation to real boiler fuel behaviour. In this paper the method of determination of slagging properties of solid fuels based on laboratory investigation and artificial neural networks were presented. A fuel data base with over 40 fuels was created. Neural networks simulations were carried out in order to predict the beginning temperature and intensity of slagging. Reasonable results were obtained for some of tested neural networks, especially for hybrid feedforward networks with PCA technique. Consequently neural network model will be used in Common Intelligent Boiler Operation Platform (CIBOP being elaborated within CERUBIS research project for two BP-1150 and BB-1150 steam boilers. The model among others enables proper fuel selection in order to minimize slagging risk.

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

    Energy Technology Data Exchange (ETDEWEB)

    Unknown

    2003-06-01

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

  13. Macro Level Modeling of a Tubular Solid Oxide Fuel Cell

    Directory of Open Access Journals (Sweden)

    Farshid Zabihian

    2010-11-01

    Full Text Available This paper presents a macro-level model of a solid oxide fuel cell (SOFC stack implemented in Aspen Plus® for the simulation of SOFC system. The model is 0-dimensional and accepts hydrocarbon fuels such as reformed natural gas, with user inputs of current density, fuel and air composition, flow rates, temperature, pressure, and fuel utilization factor. The model outputs the composition of the exhaust, work produced, heat available for the fuel reformer, and electrochemical properties of SOFC for model validation. It was developed considering the activation, concentration, and ohmic losses to be the main over-potentials within the SOFC, and mathematical expressions for these were chosen based on available studies in the literature. The model also considered the water shift reaction of CO and the methane reforming reaction. The model results were validated using experimental data from Siemens Westinghouse. The results showed that the model could capture the operating pressure and temperature dependency of the SOFC performance successfully in an operating range of 1–15 atm for pressure and 900 °C–1,000 °C for temperature. Furthermore, a sensitivity analysis was performed to identify the model constants and input parameters that impacted the over-potentials.

  14. Thermodynamic analysis of SOFC (solid oxide fuel cell) - Stirling hybrid plants using alternative fuels

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2013-01-01

    . Simulations of the proposed system were conducted using different fuels, which should facilitate the use of a variety of fuels depending on availability. Here, the results for natural gas (NG), ammonia, di-methyl ether (DME), methanol and ethanol are presented and analyzed. The system behavior is further......A novel hybrid power system (∼10 kW) for an average family home is proposed. The system investigated contains a solid oxide fuel cell (SOFC) on top of a Stirling engine. The off-gases produced in the SOFC cycle are fed to a bottoming Stirling engine, at which additional power is generated...... investigated by comparing the effects of key factors, such as the utilization factor and the operating conditions under which these fuels are used. Moreover, the effect of using a methanator on the plant efficiency is also studied. The combined system improves the overall electrical efficiency relative...

  15. Strategies for Lowering Solid Oxide Fuel Cells Operating Temperature

    Directory of Open Access Journals (Sweden)

    Albert Tarancón

    2009-11-01

    Full Text Available Lowering the operating temperature of solid oxide fuel cells (SOFCs to the intermediate range (500–700 ºC has become one of the main SOFC research goals. High operating temperatures put numerous requirements on materials selection and on secondary units, limiting the commercial development of SOFCs. The present review first focuses on the main effects of reducing the operating temperature in terms of materials stability, thermo-mechanical mismatch, thermal management and efficiency. After a brief survey of the state-of-the-art materials for SOFCs, attention is focused on emerging oxide-ionic conductors with high conductivity in the intermediate range of temperatures with an introductory section on materials technology for reducing the electrolyte thickness. Finally, recent advances in cathode materials based on layered mixed ionic-electronic conductors are highlighted because the decreasing temperature converts the cathode into the major source of electrical losses for the whole SOFC system. It is concluded that the introduction of alternative materials that would enable solid oxide fuel cells to operate in the intermediate range of temperatures would have a major impact on the commercialization of fuel cell technology.

  16. Solid-shape energy fuels from recyclable municipal solid waste and plastics

    Science.gov (United States)

    Gug, Jeongin

    Diversion of waste streams, such as plastics, wood and paper, from municipal landfills and extraction of useful materials from landfills is an area of increasing interest across the country, especially in densely populated areas. One promising technology for recycling MSW (municipal solid waste) is to burn the high energy content components in standard coal boilers. This research seeks to reform wastes into briquette that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, moisture resistance, and retain high fuel value. Household waste with high paper and fibers content was used as the base material for this study. It was combined with recyclable plastics such as PE, PP, PET and PS for enhanced binding and energy efficiency. Fuel pellets were processed using a compression molding technique. The resulting moisture absorption, proximate analysis from burning, and mechanical properties were investigated after sample production and then compared with reference data for commercial coals and biomass briquettes. The effects of moisture content, compression pressure and processing temperature were studied to identify the optimal processing conditions with water uptake tests for the durability of samples under humid conditions and burning tests to examine the composition of samples. Lastly, mechanical testing revealed the structural stability of solid fuels. The properties of fuel briquettes produced from waste and recycled plastics improved with higher processing temperature but without charring the material. Optimization of moisture content and removal of air bubbles increased the density, stability and mechanical strength. The sample composition was found to be more similar to biomass fuels than coals because the majority of the starting material was paper-based solid waste. According to the proximate analysis results, the waste fuels can be expected to have

  17. A Reversible Planar Solid Oxide Fuel-Fed Electrolysis Cell and Solid Oxide Fuel Cell for Hydrogen and Electricity Production Operating on Natural Gas/Biomass Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Greg, G.

    2007-03-31

    A solid oxide fuel-assisted electrolysis technique was developed to co-generate hydrogen and electricity directly from a fuel at a reduced cost of electricity. Solid oxide fuel-assisted electrolysis cells (SOFECs), which were comprised of 8YSZ electrolytes sandwiched between thick anode supports and thin cathodes, were constructed and experimentally evaluated at various operation conditions on lab-level button cells with 2 cm2 per-cell active areas as well as on bench-scale stacks with 30 cm2 and 100 cm2 per-cell active areas. To reduce the concentration overpotentials, pore former systems were developed and engineered to optimize the microstructure and morphology of the Ni+8YSZ-based anodes. Chemically stable cathode materials, which possess good electronic and ionic conductivity and exhibit good electrocatalytic properties in both oxidizing and reducing gas atmospheres, were developed and materials properties were investigated. In order to increase the specific hydrogen production rate and thereby reduce the system volume and capital cost for commercial applications, a hybrid system that integrates the technologies of the SOFEC and the solid-oxide fuel cell (SOFC), was developed and successfully demonstrated at a 1kW scale, co-generating hydrogen and electricity directly from chemical fuels.

  18. Production of New Biomass/Waste-Containing Solid Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Glenn A. Shirey; David J. Akers

    2005-09-23

    CQ Inc. and its industry partners--PBS Coals, Inc. (Friedens, Pennsylvania), American Fiber Resources (Fairmont, West Virginia), Allegheny Energy Supply (Williamsport, Maryland), and the Heritage Research Group (Indianapolis, Indiana)--addressed the objectives of the Department of Energy and industry to produce economical, new solid fuels from coal, biomass, and waste materials that reduce emissions from coal-fired boilers. This project builds on the team's commercial experience in composite fuels for energy production. The electric utility industry is interested in the use of biomass and wastes as fuel to reduce both emissions and fuel costs. In addition to these benefits, utilities also recognize the business advantage of consuming the waste byproducts of customers both to retain customers and to improve the public image of the industry. Unfortunately, biomass and waste byproducts can be troublesome fuels because of low bulk density, high moisture content, variable composition, handling and feeding problems, and inadequate information about combustion and emissions characteristics. Current methods of co-firing biomass and wastes either use a separate fuel receiving, storage, and boiler feed system, or mass burn the biomass by simply mixing it with coal on the storage pile. For biomass or biomass-containing composite fuels to be extensively used in the U.S., especially in the steam market, a lower cost method of producing these fuels must be developed that is applicable to a variety of combinations of biomass, wastes, and coal; economically competitive with current fuels; and provides environmental benefits compared with coal. During Phase I of this project (January 1999 to July 2000), several biomass/waste materials were evaluated for potential use in a composite fuel. As a result of that work and the team's commercial experience in composite fuels for energy production, paper mill sludge and coal were selected for further evaluation and demonstration

  19. Solid oxide fuel cell material research in SICCAS

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.; Ye, X.; Zen, F.; Li, J.; Shi, J.; Wen, T. [Chinese Academy of Sciences, Shanghai Inst. of Ceramics, Shanghai (China). CAS Key Laboratory of Materials for Energy Conversion

    2010-07-01

    A fuel cell is a device that transfers the chemical energy of fuels directly to electricity. Because its high operating temperature enables the further application of the co-generated heat, the solid oxide fuel cell (SOFC) has the highest efficiency in different types of fuel cells. SICCAS has almost 15 years of experience in the research, development and manufacture of planar type SOFCs. In order to reduce the cost, extend the life time, and propel the commercialization of SOFCs, the company is now focusing on intermediate temperature SOFCs following an international tendency in this direction. Two options for reducing the operating temperatures involve decreasing the thickness of the electrolyte or adopting new materials with higher conductivity. This paper presented a study that used both these methods to make nickel (Ni)/yttria stabilized zirconia (YSZ) anode supported scandia-stabilized zirconia electrolyte composite membranes, using an astrocyte-derived extracellullar matrix (ASECM) with the tape casting technique. In order to evaluate various cathodes, single cells were also constructed on the ASECM. It was concluded that a cell with LBSM-GDC cathode could exhibit good activity, and the output power density reached 0.738W/cm2 at 750 degrees Celsius.

  20. Solid oxide fuel cell application in district cooling

    Science.gov (United States)

    Al-Qattan, Ayman; ElSherbini, Abdelrahman; Al-Ajmi, Kholoud

    2014-07-01

    This paper presents analysis of the performance of a combined cooling and power (CCP) system for district cooling. The cogeneration system is designed to provide cooling for a low-rise residential district of 27,300 RT (96 MWc). A solid oxide fuel cell (SOFC) generates electric power to operate chillers, and the exhaust fuel and heat from the SOFC run gas turbines and absorption chillers. Thermal energy storage is utilized to reduce system capacity. Part-load operation strategies target maximizing energy efficiency. The operation of the system is compared through an hourly simulation to that of packaged air-conditioning units typically used to cool homes. The CCP system with the district cooling arrangement improves the cooling-to-fuel efficiency by 346%. The peak power requirement is reduced by 57% (24 MW) and the total fuel energy is reduced by 54% (750 TJ y-1). The system cuts annual carbon dioxide emissions to less than half and reduces other harmful emissions. A cost analysis of the system components and operation resulted in a 53% reduction in the cost per ton-hour of cooling over traditional systems.

  1. Developments in fluidized bed conversion of solid fuels

    Directory of Open Access Journals (Sweden)

    Leckner Bo

    2016-01-01

    Full Text Available A summary is given on the development of fluidized bed conversion (combustion and gasification of solid fuels. First, gasification is mentioned, following the line of development from the Winkler gasifier to recent designs. The combustors were initially bubbling beds, which were found unsuitable for combustion of coal because of various drawbacks, but they proved more useful for biomass where these drawbacks were absent. Instead, circulating fluidized bed boilers became the most important coal converters, whose design now is quite mature, and presently the increments in size and efficiency are the most important development tasks. The new modifications of these conversion devices are related to CO2 capture. Proposed methods with this purpose, involving fluidized bed, are single-reactor systems like oxy-fuel combustion, and dual-reactor systems, including also indirect biomass gasifiers.

  2. AlliedSignal solid oxide fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Minh, N.; Barr, K.; Kelly, P.; Montgomery, K. [AlliedSignal Aerospace Equipment Systems, Torrance, CA (United States)

    1996-12-31

    AlliedSignal has been developing high-performance, lightweight solid oxide fuel cell (SOFC) technology for a broad spectrum of electric power generation applications. This technology is well suited for use in a variety of power systems, ranging from commercial cogeneration to military mobile power sources. The AlliedSignal SOFC is based on stacking high-performance thin-electrolyte cells with lightweight metallic interconnect assemblies to form a compact structure. The fuel cell can be operated at reduced temperatures (600{degrees} to 800{degrees}C). SOFC stacks based on this design has the potential of producing 1 kW/kg and 1 ML. This paper summarizes the technical status of the design, manufacture, and operation of AlliedSignal SOFCs.

  3. PREPARATION AND CHARACTERIZATION OF SOLID ELECTROLYTES: FUEL CELL APPLICATIONS

    Energy Technology Data Exchange (ETDEWEB)

    Rambabu Bobba; Josef Hormes; T. Wang; Jaymes A. Baker; Donald G. Prier; Tommy Rockwood; Dinesha Hawkins; Saleem Hasan; V. Rayanki

    1997-12-31

    The intent of this project with Federal Energy Technology Center (FETC)/Morgantown Energy Technology Center (METC) is to develop research infrastructure conductive to Fuel Cell research at Southern University and A and M College, Baton Route. A state of the art research laboratory (James Hall No.123 and No.114) for energy conversion and storage devices was developed during this project duration. The Solid State Ionics laboratory is now fully equipped with materials research instruments: Arbin Battery Cycling and testing (8 channel) unit, Electrochemical Analyzer (EG and G PAR Model 273 and Solartron AC impedance analyzer), Fuel Cell test station (Globe Tech), Differential Scanning Calorimeter (DSC-10), Thermogravimetric Analyzer (TGA), Scanning Tunneling Microscope (STM), UV-VIS-NIR Absorption Spectrometer, Fluorescence Spectrometer, FT-IR Spectrometer, Extended X-ray Absorption Fine Structure (EXAFS) measurement capability at Center for Advanced Microstructure and Devices (CAMD- a multimillion dollar DOE facility), Glove Box, gas hood chamber, high temperature furnaces, hydraulic press and several high performance computers. IN particular, a high temperature furnace (Thermodyne 6000 furnace) and a high temperature oven were acquired through this project funds. The PI Dr. R Bobba has acquired additional funds from federal agencies include NSF-Academic Research Infrastructure program and other DOE sites. They have extensively used the multimillion dollar DOE facility ''Center'' for Advanced Microstructures and Devices (CAMD) for electrochemical research. The students were heavily involved in the experimental EXAFS measurements and made use of their DCM beamline for EXAFS research. The primary objective was to provide hands on experience to the selected African American undergraduate and graduate students in experimental energy research.The goal was to develop research skills and involve them in the Preparation and Characterization of Solid

  4. Electrochemical degradation, kinetics & performance studies of solid oxide fuel cells

    Science.gov (United States)

    Das, Debanjan

    Linear and Non-linear electrochemical characterization techniques and equivalent circuit modelling were carried out on miniature and sub-commercial Solid Oxide Fuel Cell (SOFC) stacks as an in-situ diagnostic approach to evaluate and analyze their performance under the presence of simulated alternative fuel conditions. The main focus of the study was to track the change in cell behavior and response live, as the cell was generating power. Electrochemical Impedance Spectroscopy (EIS) was the most important linear AC technique used for the study. The distinct effects of inorganic components usually present in hydrocarbon fuel reformates on SOFC behavior have been determined, allowing identification of possible "fingerprint" impedance behavior corresponding to specific fuel conditions and reaction mechanisms. Critical electrochemical processes and degradation mechanisms which might affect cell performance were identified and quantified. Sulfur and siloxane cause the most prominent degradation and the associated electrochemical cell parameters such as Gerisher and Warburg elements are applied respectively for better understanding of the degradation processes. Electrochemical Frequency Modulation (EFM) was applied for kinetic studies in SOFCs for the very first time for estimating the exchange current density and transfer coefficients. EFM is a non-linear in-situ electrochemical technique conceptually different from EIS and is used extensively in corrosion work, but rarely used on fuel cells till now. EFM is based on exploring information obtained from non-linear higher harmonic contributions from potential perturbations of electrochemical systems, otherwise not obtained by EIS. The baseline fuel used was 3 % humidified hydrogen with a 5-cell SOFC sub-commercial planar stack to perform the analysis. Traditional methods such as EIS and Tafel analysis were carried out at similar operating conditions to verify and correlate with the EFM data and ensure the validity of the

  5. Lanthanum Manganate Based Cathodes for Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Jørgensen, Mette Juhl

    medium frequency process in the impedance spectra, were observed. A low frequency arc related to gas diffusion limitation in a stagnant gas layer above the composite structure was detected. Finally, an inductive process, assumed to be connected to an activation process involving segregates at the triple......Composite cathodes for solid oxide fuel cells were investigated using electrochemical impedance spectroscopy and scanning electron microscopy. The aim was to study the oxygen reduction process in the electrode in order to minimise the voltage drop in the cathode. The electrodes contained...... phase boundary between electrode, electrolyte and gas phase, was found. Suggestions for further experiments and for modelling of the oxygen reduction mechanism are given....

  6. Production of gaseous fuel by pyrolysis of municipal solid waste

    Science.gov (United States)

    Crane, T. H.; Ringer, H. N.; Bridges, D. W.

    1975-01-01

    Pilot plant tests were conducted on a simulated solid waste which was a mixture of shredded newspaper, wood waste, polyethylene plastics, crushed glass, steel turnings, and water. Tests were conducted at 1400 F in a lead-bath pyrolyser. Cold feed was deaerated by compression and was dropped onto a moving hearth of molten lead before being transported to a sealed storage container. About 80 percent of the feed's organic content was converted to gaseous products which contain over 90 percent of the potential waste energy; 12 percent was converted to water; and 8 percent remained as partially pyrolyzed char and tars. Nearly half of the carbon in the feed is converted to benzene, toluene and medium-quality fuel gas, a potential credit of over $25 per ton of solid waste. The system was shown to require minimal preprocessing and less sorting then other methods.

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

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh

    2006-07-31

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

  8. Criteria for solid recovered fuels as a substitute for fossil fuels--a review.

    Science.gov (United States)

    Beckmann, Michael; Pohl, Martin; Bernhardt, Daniel; Gebauer, Kathrin

    2012-04-01

    The waste treatment, particularly the thermal treatment of waste has changed fundamentally in the last 20 years, i.e. from facilities solely dedicated to the thermal treatment of waste to facilities, which in addition to that ensure the safe plant operation and fulfill very ambitious criteria regarding emission reduction, resource recovery and energy efficiency as well. Therefore this contributes to the economic use of raw materials and due to the energy recovered from waste also to the energy provision. The development described had the consequence that waste and solid recovered fuels (SRF) has to be evaluated based on fuel criteria as well. Fossil fuels - coal, crude oil, natural gas etc. have been extensively investigated due to their application in plants for energy conversion and also due to their use in the primary industry. Thereby depending on the respective processes, criteria on fuel technical properties can be derived. The methods for engineering analysis of regular fuels (fossil fuels) can be transferred only partially to SRF. For this reason methods are being developed or adapted to current analytical methods for the characterization of SRF. In this paper the possibilities of the energetic utilization of SRF and the characterization of SRF before and during the energetic utilization will be discussed.

  9. Low Temperature, High Energy Density Micro Thin Film Solid Oxide Fuel Cell Project

    Data.gov (United States)

    National Aeronautics and Space Administration — A new type of solid oxide fuel cell based on thin film technology and ultra-thin electrolyte is being proposed to develop to realize major reductions in fuel cell...

  10. Fuel electrode for solid oxide electrolyte fuel cell. Kotai denkaishitsugata nenryo denchi no nenryo denkyoku

    Energy Technology Data Exchange (ETDEWEB)

    Sawada, A.

    1993-03-19

    Cermet mixed with nickel and stabilized zirconia (YSZ) is normally used for the fuel electrode of the high temperature solid oxide electrolyte fuel cell which uses coal gasification gas or natural gas as the primary fuel. When acidic YSZ is used as the aggregate for this electrode, however, carbon tends to precipitate to shorten the life of the fuel cell. This invention relates to means of preventing direct contact of hydrocarbon with the first porous electrode layer, wherein the first porous electrode layer containing YSZ aggregate and nickel metal or its oxide particles is formed on the surface of the solid electrolyte substrate, on which the second porous electrode layer containing basic aggregate and nickel metal or its oxide particles is formed. MgAl2O4, CaAl2O4, MgO[center dot]2TiO2, and MgO[center dot]ZrO2 are used as the basic aggregates which comprise the second porous electrode layer. 12 figs., 2 tabs.

  11. Application of Fly Ash from Solid Fuel Combustion in Concrete

    DEFF Research Database (Denmark)

    Pedersen, Kim Hougaard

    2008-01-01

    Application of Fly Ash from Solid Fuel Combustion in Concrete Kim H. Pedersen Abstract Industrial utilization of fly ash from pulverized coal combustion plays an important role in environmentally clean and cost effective power generation. Today, the primary market for fly ash utilization is as po......Application of Fly Ash from Solid Fuel Combustion in Concrete Kim H. Pedersen Abstract Industrial utilization of fly ash from pulverized coal combustion plays an important role in environmentally clean and cost effective power generation. Today, the primary market for fly ash utilization...... is as pozzolanic additive in the production of concrete. However, the residual carbon in fly ash can adsorb the air entraining admixtures (AEAs) added to enhance air entrainment in concrete in order to increase its workability and resistance toward freezing and thawing conditions. The problem has increased...... Nordjyllandsværket, unit 3; 3) post treatment of fly ash to lower its AEA adsorptivity. The foam index test is the method usually employed to determine the degree of fly ash interference with AEAs in concrete. The test involves the use of commercial AEAs and visual observation of foam stability. These facts reduce...

  12. Electrode Design for Low Temperature Direct-Hydrocarbon Solid Oxide Fuel Cells

    Science.gov (United States)

    Chen, Fanglin (Inventor); Zhao, Fei (Inventor); Liu, Qiang (Inventor)

    2015-01-01

    In certain embodiments of the present disclosure, a solid oxide fuel cell is described. The solid oxide fuel cell includes a hierarchically porous cathode support having an impregnated cobaltite cathode deposited thereon, an electrolyte, and an anode support. The anode support includes hydrocarbon oxidation catalyst deposited thereon, wherein the cathode support, electrolyte, and anode support are joined together and wherein the solid oxide fuel cell operates a temperature of 600.degree. C. or less.

  13. Tecnored process - high potential in using different kinds of solid fuels

    Directory of Open Access Journals (Sweden)

    José Henrique Noldin Júnior

    2005-12-01

    Full Text Available One important feature of the Brazilian Tecnored ironmaking process is its flexibility to use different types of solid fuels, other than metallurgical coke, as proved in the pilot plant tests by extensively using green petroleum coke, biomasses, high ash cokes, etc. Even if new solid fuels not thus far used are envisaged for a given project, thru the bench scale simulator of the process it is possible to predict the behavior of such solid fuels in the Tecnored furnace and establish the best techno-economical-environmental equation for its use. This paper discusses the key aspects involved in the use of alternative solid fuels in the Tecnored process.

  14. Evaluation of apatite silicates as solid oxide fuel cell electrolytes

    Energy Technology Data Exchange (ETDEWEB)

    Marrero-Lopez, D. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain); Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Martin-Sedeno, M.C.; Aranda, M.A.G. [Dpto. de Quimica Inorganica, Universidad Malaga, 29071 Malaga (Spain); Pena-Martinez, J. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Instituto de Energias Renovables, Parque Tecnologico, Universidad de Castilla La Mancha, 02006 Albacete (Spain); Ruiz-Morales, J.C.; Nunez, P. [Dpto. de Quimica Inorganica, Universidad de La Laguna, 38200 La Laguna, Tenerife (Spain); Ramos-Barrado, J.R. [Dpto. de Fisica Aplicada I, Laboratorio de Materiales y Superficies (Unidad Asociada al C.S.I.C.), Universidad de Malaga, 29071 Malaga (Spain)

    2010-05-01

    Apatite-type silicates have been considered as promising electrolytes for Solid Oxide Fuel Cells (SOFC); however studies on the potential use of these materials in SOFC devices have received relatively little attention. The lanthanum silicate with composition La{sub 10}Si{sub 5.5}Al{sub 0.5}O{sub 26.75} has been evaluated as electrolyte with the electrode materials commonly used in SOFC, i.e. manganite, ferrite and cobaltite as cathode materials and NiO-CGO composite, chromium-manganite and Sr{sub 2}MgMoO{sub 6} as anode materials. Chemical compatibility, area-specific resistance and fuel cell studies have been performed. X-ray powder diffraction (XRPD) analysis did not reveal any trace of reaction products between the apatite electrolyte and most of the aforementioned electrode materials. However, the area-specific polarisation resistance (ASR) of these electrodes in contact with apatite electrolyte increased significantly with the sintering temperature, indicating reactivity at the electrolyte/electrode interface. On the other hand, the ASR values are significantly improved using a ceria buffer layer between the electrolyte and electrode materials to prevent reactivity. Maximum power densities of 195 and 65 mWcm{sup -2} were obtained at 850 and 700 C, respectively in H{sub 2} fuel, using an 1 mm-thick electrolyte, a NiO-Ce{sub 0.8}Gd{sub 0.2}O{sub 1.9} composite as anode and La{sub 0.6}Sr{sub 0.4}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} as cathode materials. This fuel cell was tested for 100 h in 5%H{sub 2}-Ar atmosphere showing stable performance. (author)

  15. Strong, Tough Glass Composites Developed for Solid Oxide Fuel Cell Seals

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2005-01-01

    A fuel cell is an electrochemical device that continuously converts the chemical energy of a fuel directly into electrical energy. It consists of an electrolyte, an anode, and a cathode. Various types of fuel cells are available, such as direct methanol fuel cells, alkaline fuel cells, proton-exchange-membrane fuel cells, phosphoric acid fuel cells, molten carbonate fuel cells, and solid oxide fuel cells (SOFCs). The salient features of an SOFC are all solid construction and high-temperature electrochemical-reaction-based operation, resulting in clean, efficient power generation from a variety of fuels. SOFCs are being developed for a broad range of applications, such as portable electronic devices, automobiles, power generation, and aeronautics.

  16. On the Piloted Ignition of Solid Fuels in Spacecraft Environments

    Science.gov (United States)

    Fereres-Rapoport, Sonya M.

    The effect of environmental variables on the ignition of solid combustible materials is explored through a combination of experimental, analytical and numerical analyses. This research stems from NASA's design requirement to reduce the cabin internal pressure and increase the oxygen concentration in human space vehicles and in future lunar habitats of the Constellation Program. These new environmental conditions may result in an increased fire risk of combustible solid materials due to higher flame temperatures (attributed to enhanced oxygen) and reduced convective heat losses from heated surfaces (attributed to reduced pressure). In particular, the influence of low pressure on ignition is emphasized here because little is known concerning this topic. A series of experiments conducted in a laboratory-scale combustion wind tunnel with externally irradiated samples of PMMA (polymethyl-methacrylate) showed that both the ignition delay time and the fuel mass flux at ignition decrease when the ambient pressure is lowered. An analytical model is used to identify the governing processes that lead to these results and then a numerical model is applied to quantify the influence of ambient variables (particularly pressure) on the piloted ignition of PMMA. The numerical model verifies the phenomenological explanations inferred from the experimental findings and the qualitative analytical results, and correctly simulates the thermo-physical mechanisms leading to ignition. It is concluded that reduced pressure environments result in: (1) smaller convective heat losses from the heated material to the surroundings due to a thickening of the thermal boundary layer next to the solid fuel surface, allowing for the material to heat more rapidly and pyrolyze faster; and, (2) a lower mass flux of volatiles required to reach the lean flammability limit of the gases at the pilot, leading to earlier ignition, due mainly to an enlarged boundary layer and a thicker fuel species profile

  17. Municipal Solid Waste Gasification with Solid Oxide Fuel Cells and Stirling Engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    storage in landfills and devote these spaces to other human activities. It is also important to point out that this kind of renewable energy suffers significantly less availabilit y which characterizes other type o f renewable energy sources such as in wind and solar energy. In a gasification process....... The gasification process is usually based on an atmospheric - pressure circulating fluidized bed gasifier coupled to a tar - crac king vessel. Syngas can be used as fuel in different kind of power plant such as gas turbine cycle, steam cycle, combined cycle, internal and external combustion engine and Solid Oxide...... Fuel Cell (SOFC). In the present study, a MSW gasification plant int egrated with SOFC is combined with a Stirling engine to recover the energy of the off - gases from the topping SOFC cycle. Detailed plant design is proposed and thermodynamic analysis is performed. Relevant parameters have been...

  18. Sampling, characterisation and processing of solid recovered fuel production from municipal solid waste: An Italian plant case study.

    Science.gov (United States)

    Ranieri, Ezio; Ionescu, Gabriela; Fedele, Arcangela; Palmieri, Eleonora; Ranieri, Ada Cristina; Campanaro, Vincenzo

    2017-08-01

    This article presents the classification of solid recovered fuel from the Massafra municipal solid waste treatment plant in Southern Italy in compliancy with the EN 15359 standard. In order to ensure the reproducibility of this study, the characterisation methods of waste input and output flow, the mechanical biological treatment line scheme and its main parameters for each stage of the processing chain are presented in details, together with the research results in terms of mass balance and derived fuel properties. Under this study, only 31% of refused municipal solid waste input stream from mechanical biological line was recovered as solid recovered fuel with a net heating value (NC=HV) average of 15.77 MJ kg -1 ; chlorine content average of 0.06% on a dry basis; median of mercury fuel produced meets the European Union standard requirements and can be classified with the class code: Net heating value (3); chlorine (1); mercury (1).

  19. Recovery of solid fuel from municipal solid waste by hydrothermal treatment using subcritical water.

    Science.gov (United States)

    Hwang, In-Hee; Aoyama, Hiroya; Matsuto, Toshihiko; Nakagishi, Tatsuhiro; Matsuo, Takayuki

    2012-03-01

    Hydrothermal treatments using subcritical water (HTSW) such as that at 234°C and 3MPa (LT condition) and 295°C and 8MPa (HT condition) were investigated to recover solid fuel from municipal solid waste (MSW). Printing paper, dog food (DF), wooden chopsticks, and mixed plastic film and sheets of polyethylene, polypropylene, and polystyrene were prepared as model MSW components, in which polyvinylchloride (PVC) powder and sodium chloride were used to simulate Cl sources. While more than 75% of carbon in paper, DF, and wood was recovered as char under both LT and HT conditions, plastics did not degrade under either LT or HT conditions. The heating value (HV) of obtained char was 13,886-27,544 kJ/kg and was comparable to that of brown coal and lignite. Higher formation of fixed carbon and greater oxygen dissociation during HTSW were thought to improve the HV of char. Cl atoms added as PVC powder and sodium chloride to raw material remained in char after HTSW. However, most Cl originating from PVC was found to converse into soluble Cl compounds during HTSW under the HT condition and could be removed by washing. From these results, the merit of HTSW as a method of recovering solid fuel from MSW is considered to produce char with minimal carbon loss without a drying process prior to HTSW. In addition, Cl originating from PVC decomposes into soluble Cl compound under the HT condition. The combination of HTSW under the HT condition and char washing might improve the quality of char as alternative fuel. Copyright © 2011 Elsevier Ltd. All rights reserved.

  20. Solid oxide fuel cell having a glass composite seal

    Science.gov (United States)

    De Rose, Anthony J.; Mukerjee, Subhasish; Haltiner, Jr., Karl Jacob

    2013-04-16

    A solid oxide fuel cell stack having a plurality of cassettes and a glass composite seal disposed between the sealing surfaces of adjacent cassettes, thereby joining the cassettes and providing a hermetic seal therebetween. The glass composite seal includes an alkaline earth aluminosilicate (AEAS) glass disposed about a viscous glass such that the AEAS glass retains the viscous glass in a predetermined position between the first and second sealing surfaces. The AEAS glass provides geometric stability to the glass composite seal to maintain the proper distance between the adjacent cassettes while the viscous glass provides for a compliant and self-healing seal. The glass composite seal may include fibers, powders, and/or beads of zirconium oxide, aluminum oxide, yttria-stabilized zirconia (YSZ), or mixtures thereof, to enhance the desirable properties of the glass composite seal.

  1. Solid Oxide Fuel Cell Seal Glass - BN Nanotubes Composites

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.; Hurst, Janet B.; Garg, Anita

    2005-01-01

    Solid oxide fuel cell seal glass G18 composites reinforced with approx.4 weight percent of BN nanotubes were fabricated via hot pressing. Room temperature strength and fracture toughness of the composite were determined by four-point flexure and single edge V-notch beam methods, respectively. The strength and fracture toughness of the composite were higher by as much as 90% and 35%, respectively, than those of the glass G18. Microscopic examination of the composite fracture surfaces using SEM and TEM showed pullout of the BN nanotubes, similar in feature to fiber-reinforced ceramic matrix composites with weak interfaces. Other mechanical and physical properties of the composite will also be presented.

  2. Failure analysis of electrolyte-supported solid oxide fuel cells

    Science.gov (United States)

    Fleischhauer, Felix; Tiefenauer, Andreas; Graule, Thomas; Danzer, Robert; Mai, Andreas; Kuebler, Jakob

    2014-07-01

    For solid oxide fuel cells (SOFCs) one key aspect is the structural integrity of the cell and hence its thermo mechanical long term behaviour. The present study investigates the failure mechanisms and the actual causes for fracture of electrolyte supported SOFCs which were run using the current μ-CHP system of Hexis AG, Winterthur - Switzerland under lab conditions or at customer sites for up to 40,000 h. In a first step several operated stacks were demounted for post-mortem inspection, followed by a fractographic evaluation of the failed cells. The respective findings are then set into a larger picture including an analysis of the present stresses acting on the cell like thermal and residual stresses and the measurements regarding the temperature dependent electrolyte strength. For all investigated stacks, the mechanical failure of individual cells can be attributed to locally acting bending loads, which rise due to an inhomogeneous and uneven contact between the metallic interconnect and the cell.

  3. Fabrication and characterization of monolithic solid oxide fuel cells

    Science.gov (United States)

    Minh, N. Q.; Horne, C. R.; Liu, F. S.; Moffatt, D. M.; Staszak, P. R.

    The monolithic solid oxide fuel cell (MSOFC) is an all-ceramic structure in which cell components are configured in a compact corrugated array. The MSOFC shows promise for use in a wide range of sizes (kilowatt to megawatt) and a broad spectrum of applications (electric utility, cogeneration, on-site, and aerospace power). A process based on the tape calendering technique is being developed for the fabrication of the MSOFC. MSOFC single cells have been fabricated by this process without cracking or delamination. Stacks of various sizes have been formed and processed to demonstrate fabricability of the monolithic structure. Extensive physical, chemical, electrical, and electrochemical characterization of fabricated samples has been carried out to confirm the required properties of each cell component. The characterization results reported have been used to support material and fabrication improvements.

  4. Anodes for Solid Oxide Fuel Cells Operating at Low Temperatures

    DEFF Research Database (Denmark)

    Abdul Jabbar, Mohammed Hussain

    . On the other hand, low-temperature operation poses serious challenges to the electrode performance. Effective catalysts, redox stable electrodes with improved microstructures are the prime requisite for the development of efficient SOFC anodes. The performance of Nb-doped SrT iO3 (STN) ceramic anodes......An important issue that has limited the potential of Solid Oxide Fuel Cells (SOFCs) for portable applications is its high operating temperatures (800-1000 ºC). Lowering the operating temperature of SOFCs to 400-600 ºC enable a wider material selection, reduced degradation and increased lifetime...... at 400ºC. The potential of using WO3 ceramic as an alternative anode materials has been explored. The relatively high electrode polarization resistance obtained, 11 Ohm cm2 at 600 ºC, proved the inadequate catalytic activity of this system for hydrogen oxidation. At the end of this thesis...

  5. ALTERNATIVE METHODS OF SEALING PLANAR SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Weil, K. Scott; Coyle, Christopher A.; Hardy, John S.; Kim, Jin Yong Y.; Xia, Gordon

    2005-03-01

    One of the key limiting issues in designing and fabricating a high performance planar solid oxide fuel cell (pSOFC) stack is the development of the appropriate materials and techniques for hermetically sealing the metal and ceramic components. There are essentially two standard methods of sealing: (1) by forming a rigid joint or (2) by constructing a compressive “sliding” seal. While short-term success has been achieved with both techniques, it is apparent that to meet the long-term operational needs of stack designers, alternative sealing concepts will need to be conceived. Described below are two alternative pSOFC sealing methods that have been developed at Pacific Northwest National Laboratory.

  6. Novel nano-network cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Fei [Laboratory for Renewable Clean Energy, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, Anhui (China); Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States); Wang, Zhiyong; Liu, Mingfei; Zhang, Lei; Xia, Changrong [Laboratory for Renewable Clean Energy, Department of Materials Science and Engineering, University of Science and Technology of China, Hefei 230026, Anhui (China); Chen, Fanglin [Department of Mechanical Engineering, University of South Carolina, Columbia, SC 29208 (United States)

    2008-10-15

    A novel nano-network of Sm{sub 0.5}Sr{sub 0.5}CoO{sub 3-{delta}} (SSC) is successfully fabricated as the cathodes for intermediate-temperature solid oxide fuel cells (SOFCs) operated at 500-600 C. The cathode is composed of SSC nanowires formed from nanobeads of less than 50 nm thus exhibiting high surface area and porosity, forming straight path for oxygen ion and electron transportation, resulting in high three-phase boundaries, and consequently showing remarkably high electrode performance. An anode-supported cell with the nano-network cathode demonstrates a peak power density of 0.44 W cm{sup -2} at 500 C and displays exceptional performance with cell operating time. The result suggests a new direction to significantly improve the SOFC performance. (author)

  7. Quantification of fusion in ashes from solid fuel combustion

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug; Frandsen, Flemming; Dam-Johansen, Kim

    1999-01-01

    , for which the agreement with fusion as determined by phase diagrams is very good, and for straw (salt-rich) and coal (silicate-rich) ashes. Comparing ash fusion curves to index points of current standard ash fusion tests showed initial melting at temperatures typically between 50 degrees and 100 degrees C......The fusion of ashes produced during solid fuel combustion greatly affects the tendency of these ashes to cause operational problems in utility boilers. In this paper, a new and quantitative laboratory method for assessing the fusion of ashes based on simultaneous thermal analysis, STA, is described....... Using STA, melting is detected as an endothermic reaction involving no change in mass. The measurement signals are transferred into a fusion curve showing the melt fraction in the ash as a function of temperature. This is done either by a simple comparison of the energies used for melting in different...

  8. Strength of Anode‐Supported Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Faes, A.; Frandsen, Henrik Lund; Kaiser, Andreas

    2011-01-01

    Nickel oxide and yttria doped zirconia composite strength is crucial for anode‐supported solid oxide fuel cells, especially during transient operation, but also for the initial stacking process, where cell curvature after sintering can cause problems. This work first compares tensile and ball......‐on‐ring strength measurements of as‐sintered anodes support. Secondly, the strength of anode support sintered alone is compared to the strength of a co‐sintered anode support with anode and electrolyte layers. Finally, the orientation of the specimens to the bending axis of a co‐sintered half‐cell is investigated....... Even though the electrolyte is to the tensile side, it is found that the anode support fails due to the thermo‐mechanical residual stresses....

  9. Recovery of solid fuel from municipal solid waste by hydrothermal treatment using subcritical water

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, In-Hee, E-mail: hwang@eng.hokudai.ac.jp [Laboratory of Solid Waste Disposal Engineering, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060 8628 (Japan); Aoyama, Hiroya; Matsuto, Toshihiko; Nakagishi, Tatsuhiro; Matsuo, Takayuki [Laboratory of Solid Waste Disposal Engineering, Faculty of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060 8628 (Japan)

    2012-03-15

    Highlights: Black-Right-Pointing-Pointer Hydrothermal treatment using subcritical water was studied to recover solid fuel from MSW. Black-Right-Pointing-Pointer More than 75% of carbon in MSW was recovered as char. Black-Right-Pointing-Pointer Heating value of char was comparable to that of brown coal and lignite. Black-Right-Pointing-Pointer Polyvinyl chloride was decomposed at 295 Degree-Sign C and 8 MPa and was removed by washing. - Abstract: Hydrothermal treatments using subcritical water (HTSW) such as that at 234 Degree-Sign C and 3 MPa (LT condition) and 295 Degree-Sign C and 8 MPa (HT condition) were investigated to recover solid fuel from municipal solid waste (MSW). Printing paper, dog food (DF), wooden chopsticks, and mixed plastic film and sheets of polyethylene, polypropylene, and polystyrene were prepared as model MSW components, in which polyvinylchloride (PVC) powder and sodium chloride were used to simulate Cl sources. While more than 75% of carbon in paper, DF, and wood was recovered as char under both LT and HT conditions, plastics did not degrade under either LT or HT conditions. The heating value (HV) of obtained char was 13,886-27,544 kJ/kg and was comparable to that of brown coal and lignite. Higher formation of fixed carbon and greater oxygen dissociation during HTSW were thought to improve the HV of char. Cl atoms added as PVC powder and sodium chloride to raw material remained in char after HTSW. However, most Cl originating from PVC was found to converse into soluble Cl compounds during HTSW under the HT condition and could be removed by washing. From these results, the merit of HTSW as a method of recovering solid fuel from MSW is considered to produce char with minimal carbon loss without a drying process prior to HTSW. In addition, Cl originating from PVC decomposes into soluble Cl compound under the HT condition. The combination of HTSW under the HT condition and char washing might improve the quality of char as alternative fuel.

  10. Processing and properties of a solid energy fuel from municipal solid waste (MSW) and recycled plastics.

    Science.gov (United States)

    Gug, JeongIn; Cacciola, David; Sobkowicz, Margaret J

    2015-01-01

    Diversion of waste streams such as plastics, woods, papers and other solid trash from municipal landfills and extraction of useful materials from landfills is an area of increasing interest especially in densely populated areas. One promising technology for recycling municipal solid waste (MSW) is to burn the high-energy-content components in standard coal power plant. This research aims to reform wastes into briquettes that are compatible with typical coal combustion processes. In order to comply with the standards of coal-fired power plants, the feedstock must be mechanically robust, free of hazardous contaminants, and moisture resistant, while retaining high fuel value. This study aims to investigate the effects of processing conditions and added recyclable plastics on the properties of MSW solid fuels. A well-sorted waste stream high in paper and fiber content was combined with controlled levels of recyclable plastics PE, PP, PET and PS and formed into briquettes using a compression molding technique. The effect of added plastics and moisture content on binding attraction and energy efficiency were investigated. The stability of the briquettes to moisture exposure, the fuel composition by proximate analysis, briquette mechanical strength, and burning efficiency were evaluated. It was found that high processing temperature ensures better properties of the product addition of milled mixed plastic waste leads to better encapsulation as well as to greater calorific value. Also some moisture removal (but not complete) improves the compacting process and results in higher heating value. Analysis of the post-processing water uptake and compressive strength showed a correlation between density and stability to both mechanical stress and humid environment. Proximate analysis indicated heating values comparable to coal. The results showed that mechanical and moisture uptake stability were improved when the moisture and air contents were optimized. Moreover, the briquette

  11. Physicochemical characteristics of various inorganic combustible solid waste (ICSW) mixed as sustainable solid fuel

    Science.gov (United States)

    Sukarni, Sumarli, Puspitasari, Poppy; Suryanto, Heru; Wati, Rita Fajar

    2017-09-01

    The potential of inorganic combustible solid waste (ICSW) as sustainable solid fuel regarding its physical and chemical properties have investigated. The physical characterization was obtained by conducting the proximate test using Differential Thermal Analysis (DTA). This ICSW showed excellent physical properties, which its water, volatile, fixed carbon and ash content were 2.25, 65.45, 28.94 and 3.36 (wt%, air dry basis), respectively. The calorific value of 33.87 MJ/kg was found in the ICSW, which it to be comparable to the medium class of bituminous coal. The energy density of ICSW was 3612,8 MJ/m3. The ICSW chemical properties, which analyzed by using energy dispersive X-ray (EDX) spectrometry, indicated that it has a high content of C (79,49 wt%) and relatively small content of incombustible ingredient.

  12. Glass/Ceramic Composites for Sealing Solid Oxide Fuel Cells

    Science.gov (United States)

    Bansal, Narottam P.; Choi, Sung R.

    2007-01-01

    A family of glass/ceramic composite materials has been investigated for use as sealants in planar solid oxide fuel cells. These materials are modified versions of a barium calcium aluminosilicate glass developed previously for the same purpose. The composition of the glass in mole percentages is 35BaO + 15CaO + 5Al2O3 + 10B2O3 + 35SiO2. The glass seal was found to be susceptible to cracking during thermal cycling of the fuel cells. The goal in formulating the glass/ ceramic composite materials was to (1) retain the physical and chemical advantages that led to the prior selection of the barium calcium aluminosilicate glass as the sealant while (2) increasing strength and fracture toughness so as to reduce the tendency toward cracking. Each of the composite formulations consists of the glass plus either of two ceramic reinforcements in a proportion between 0 and 30 mole percent. One of the ceramic reinforcements consists of alumina platelets; the other one consists of particles of yttria-stabilized zirconia wherein the yttria content is 3 mole percent (3YSZ). In preparation for experiments, panels of the glass/ceramic composites were hot-pressed and machined into test bars.

  13. Integrated Solid Oxide Fuel Cell Power System Characteristics Prediction

    Directory of Open Access Journals (Sweden)

    Marian GAICEANU

    2009-07-01

    Full Text Available The main objective of this paper is to deduce the specific characteristics of the CHP 100kWe Solid Oxide Fuel Cell (SOFC Power System from the steady state experimental data. From the experimental data, the authors have been developed and validated the steady state mathematical model. From the control room the steady state experimental data of the SOFC power conditioning are available and using the developed steady state mathematical model, the authors have been obtained the characteristic curves of the system performed by Siemens-Westinghouse Power Corporation. As a methodology the backward and forward power flow analysis has been employed. The backward power flow makes possible to obtain the SOFC power system operating point at different load levels, resulting as the load characteristic. By knowing the fuel cell output characteristic, the forward power flow analysis is used to predict the power system efficiency in different operating points, to choose the adequate control decision in order to obtain the high efficiency operation of the SOFC power system at different load levels. The CHP 100kWe power system is located at Gas Turbine Technologies Company (a Siemens Subsidiary, TurboCare brand in Turin, Italy. The work was carried out through the Energia da Ossidi Solidi (EOS Project. The SOFC stack delivers constant power permanently in order to supply the electric and thermal power both to the TurboCare Company and to the national grid.

  14. Solid oxide fuel cell performance under severe operating conditions

    DEFF Research Database (Denmark)

    Koch, Søren; Hendriksen, P.V.; Mogensen, Mogens Bjerg

    2006-01-01

    The performance and degradation of Solid Oxide Fuel Cells (SOFC) were studied under severe operating conditions. The cells studied were manufactured in a small series by ECN, in the framework of the EU funded CORE-SOFC project. The cells were of the anode-supported type with a double layer LSM...... cathode. They were operated at 750 °C or 850 °C in hydrogen with 5% or 50% water at current densities ranging from 0.25 A cm–2 to 1 A cm–2 for periods of 300 hours or more. The area specific cell resistance, corrected for fuel utilisation, ranged between 0.20 Ω cm2 and 0.34 Ω cm2 at 850 °C and 520 m......V, and between 0.51 Ω cm2 and 0.92 Ω cm2 at 750 °C and 520 mV. The degradation of cell performance was found to be low (ranging from 0 to 8%/1,000 hours) at regular operating conditions. Voltage degradation rates of 20 to 40%/1,000 hours were observed under severe operating conditions, depending on the test...

  15. PRESSURIZED SOLID OXIDE FUEL CELL/GAS TURBINE POWER SYSTEM

    Energy Technology Data Exchange (ETDEWEB)

    W.L. Lundberg; G.A. Israelson; R.R. Moritz(Rolls-Royce Allison); S.E. Veyo; R.A. Holmes; P.R. Zafred; J.E. King; R.E. Kothmann (Consultant)

    2000-02-01

    Power systems based on the simplest direct integration of a pressurized solid oxide fuel cell (SOFC) generator and a gas turbine (GT) are capable of converting natural gas fuel energy to electric power with efficiencies of approximately 60% (net AC/LHV), and more complex SOFC and gas turbine arrangements can be devised for achieving even higher efficiencies. The results of a project are discussed that focused on the development of a conceptual design for a pressurized SOFC/GT power system that was intended to generate 20 MWe with at least 70% efficiency. The power system operates baseloaded in a distributed-generation application. To achieve high efficiency, the system integrates an intercooled, recuperated, reheated gas turbine with two SOFC generator stages--one operating at high pressure, and generating power, as well as providing all heat needed by the high-pressure turbine, while the second SOFC generator operates at a lower pressure, generates power, and provides all heat for the low-pressure reheat turbine. The system cycle is described, major system components are sized, the system installed-cost is estimated, and the physical arrangement of system components is discussed. Estimates of system power output, efficiency, and emissions at the design point are also presented, and the system cost of electricity estimate is developed.

  16. Metal Interconnects for Solid Oxide Fuel Cell Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    S. Elangovan

    2006-04-01

    Interconnect development is identified by the US Department of energy as a key technical area requiring focused research to meet the performance and cost goals under the Solid State Energy Conversion Alliance initiative. In the Phase I SECA Core Technology Program, Ceramatec investigated a commercial ferritic stainless steel composition for oxidation resistance properties by measuring the weight gain when exposed to air at the fuel cell operating temperature. A pre-treatment process that results in a dense, adherent scale was found to reduce the oxide scale growth rate significantly. A process for coating the surface of the alloy in order to reduce the in-plane resistance and potentially inhibit chromium oxide evaporation was also identified. The combination of treatments provided a very low resistance through the scale. The resistance measured was as low as 10 milliohm-cm2 at 750 C in air. The oxide scale was also found to be stable in humidified air at 750 C. The resistance value was stable over several thermal cycles. A similar treatment and coating for the fuel side of the interconnect also showed an exceptionally low resistance of one milliohm-cm2 in humidified hydrogen at 750 c, and was stable through multiple thermal cycles. Measurement of interconnect resistance when it was exposed to both air and humidified hydrogen on opposite sides also showed low, stable resistance after additional modification to the pre-treatment process. Resistance stacks, using an interconnect stack with realistic gas flows, also provided favorable results. Chromium evaporation issue however requires testing of fuel stacks and was outside of the scope of this project. based on results to-date, the alloy selection and the treatment processes appear to be well suited for SOFC interconnect application.

  17. Biomass-powered Solid Oxide Fuel Cells : Experimental and Modeling Studies for System Integrations

    NARCIS (Netherlands)

    Liu, M.

    2013-01-01

    Biomass is a sustainable energy source which, through thermo-chemical processes of biomass gasification, is able to be converted from a solid biomass fuel into a gas mixture, known as syngas or biosyngas. A solid oxide fuel cell (SOFC) is a power generation device that directly converts the chemical

  18. Operation of real landfill gas fueled solid oxide fuel cell (SOFC) using internal dry reforming

    DEFF Research Database (Denmark)

    Langnickel, Hendrik; Hagen, Anke

    2017-01-01

    Biomass is one renewable energy source, which is independent from solar radiation and wind effect. Solid oxide fuel cells (SOFC’s) are able to convert landfill gas derived from landfill directly into electricity and heat with a high efficiency. In the present work a planar 16cm2 SOFC cell...... was operated with a real landfill gas from one of the largest Danish waste dump sites and additional carbon dioxide reforming agent at 750˚C, both with gas cleaning through an active carbon filter and without. The tests showed an electric efficiency up to ~60%. It was found that the active carbon filter...

  19. Direct oxidation of waste vegetable oil in solid-oxide fuel cells

    Science.gov (United States)

    Zhou, Z. F.; Kumar, R.; Thakur, S. T.; Rudnick, L. R.; Schobert, H.; Lvov, S. N.

    Solid-oxide fuel cells with ceria, ceria-Cu, and ceria-Rh anode were demonstrated to generate stable electric power with waste vegetable oil through direct oxidation of the fuel. The only pre-treatment to the fuel was a filtration to remove particulates. The performance of the fuel cell was stable over 100 h for the waste vegetable oil without dilution. The generated power was up to 0.25 W cm -2 for ceria-Rh fuel cell. This compares favorably with previously studied hydrocarbon fuels including jet fuels and Pennsylvania crude oil.

  20. Novel materials for more robust solid oxide fuel cells in small scale applications

    DEFF Research Database (Denmark)

    Holtappels, Peter

    Solid oxide fuel cells can offer supply of electrical energy with a high efficiency and based on a wide range of fuels. While natural gas and/or bio methane is a commonly used fuel for combined heat and power supply, liquid fuels such as gasoline, Diesel and alcohols are interesting fuels...... hydrocarbons, coking tolerant electrodes are required. State-of art fuel electrodes are based on a nickel ceramic composite, a nickel cermet, which suffers from low redox stability, susceptibility for sulfur poisoning and coking. Redox stable anodes can be achieved by replacing the Ni-cermet fuel electrode...

  1. Designing and optimization of a micro CHP system based on Solid Oxide Fuel Cell with different fuel processing technologies

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2009-01-01

    The development of fuel cell technologies offers the opportunity to achieve significant improvements in energy conversion efficiencies at many scales. The high operating temperature (700-1000 Celsius) of Solid Oxide Fuel Cells (SOFC) has a number of consequences, the most important of which...... will be evaluated in terms of their energetic performance and suitability for meeting residential thermal and electric demand....

  2. Understanding Our Energy Footprint: Undergraduate Chemistry Laboratory Investigation of Environmental Impacts of Solid Fossil Fuel Wastes

    Science.gov (United States)

    Berger, Michael; Goldfarb, Jillian L.

    2017-01-01

    Engaging undergraduates in the environmental consequences of fossil fuel usage primes them to consider their own anthropogenic impact, and the benefits and trade-offs of converting to renewable fuel strategies. This laboratory activity explores the potential contaminants (both inorganic and organic) present in the raw fuel and solid waste…

  3. Analysis of Gas Leakage and Current Loss of Solid Oxide Fuel Cells by Screen Printing

    DEFF Research Database (Denmark)

    Jia, Chuan; Han, Minfang; Chen, Ming

    2017-01-01

    One of the biggest advantages of SOFC (solid oxide fuel cell) is the probable use of methane as fuel. However, when the actual SOFC stack is operating with CH4 as fuel, due to the catalytic action of metal nickel, carbon will deposit on SOFC anode and nickel foam, which directly shorten the SOFC ...

  4. Investigation on the effect of diaphragm on the combustion characteristics of solid-fuel ramjet

    Science.gov (United States)

    Gong, Lunkun; Chen, Xiong; Yang, Haitao; Li, Weixuan; Zhou, Changsheng

    2017-10-01

    The flow field characteristics and the regression rate distribution of solid-fuel ramjet with three-hole diaphragm were investigated by numerical and experimental methods. The experimental data were obtained by burning high-density polyethylene using a connected-pipe facility to validate the numerical model and analyze the combustion efficiency of the solid-fuel ramjet. The three-dimensional code developed in the present study adopted three-order MUSCL and central difference schemes, AUSMPW + flux vector splitting method, and second-order moment turbulence-chemistry model, together with k-ω shear stress transport (SST) turbulence model. The solid fuel surface temperature was calculated with fluid-solid heat coupling method. The numerical results show that strong circumferential flow exists in the region upstream of the diaphragm. The diaphragm can enhance the regression rate of the solid fuel in the region downstream of the diaphragm significantly, which mainly results from the increase of turbulent viscosity. As the diaphragm port area decreases, the regression rate of the solid fuel downstream of the diaphragm increases. The diaphragm can result in more sufficient mixing between the incoming air and fuel pyrolysis gases, while inevitably producing some pressure loss. The experimental results indicate that the effect of the diaphragm on the combustion efficiency of hydrocarbon fuels is slightly negative. It is conjectured that the diaphragm may have some positive effects on the combustion efficiency of the solid fuel with metal particles.

  5. The effect of electrode infiltration on the performance of tubular solid oxide fuel cells under electrolysis and fuel cell modes

    OpenAIRE

    Hanifi, Amir R.; Laguna-Bercero, M. A.; Etsell, Thomas H.; Sarkar, Partha

    2014-01-01

    The electrochemical performance of two different anode supported tubular cells (50:50 wt% NiO:YSZ (yttria stabilized zirconia) or 34:66 vol.% Ni:YSZ) as the fuel electrode and YSZ as the electrolyte) under SOFC (solid oxide fuel cell) and SOEC (solid oxide electrolysis cell) modes were studied in this research. LSM (La0.80Sr0.20MnO3-δ) was infiltrated into a thin porous YSZ layer to form the oxygen electrode of both cells and, in addition, SDC (Sm0.2Ce0.8O1.9) was infiltrated into the fuel el...

  6. Functionally Graded Cathodes for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Harry Abernathy; Meilin Liu

    2006-12-31

    One primary suspected cause of long-term performance degradation of solid oxide fuels (SOFCs) is the accumulation of chromium (Cr) species at or near the cathode/electrolyte interface due to reactive Cr molecules originating from Cr-containing components (such as the interconnect) in fuel cell stacks. To date, considerable efforts have been devoted to the characterization of cathodes exposed to Cr sources; however, little progress has been made because a detailed understanding of the chemistry and electrochemistry relevant to the Cr-poisoning processes is still lacking. This project applied multiple characterization methods - including various Raman spectroscopic techniques and various electrochemical performance measurement techniques - to elucidate and quantify the effect of Cr-related electrochemical degradation at the cathode/electrolyte interface. Using Raman microspectroscopy the identity and location of Cr contaminants (SrCrO{sub 4}, (Mn/Cr){sub 3}O{sub 4} spinel) have been observed in situ on an LSM cathode. These Cr contaminants were shown to form chemically (in the absence of current flowing through the cell) at temperatures as low as 625 C. While SrCrO{sub 4} and (Mn/Cr){sub 3}O{sub 4} spinel must preferentially form on LSM, since the LSM supplies the Sr and Mn cations necessary for these compounds, LSM was also shown to be an active site for the deposition of Ag{sub 2}CrO{sub 4} for samples that also contained silver. In contrast, Pt and YSZ do not appear to be active for formation of Cr-containing phases. The work presented here supports the theory that Cr contamination is predominantly chemically-driven and that in order to minimize the effect, cathode materials should be chosen that are free of cations/elements that could preferentially react with chromium, including silver, strontium, and manganese.

  7. Solid polymer fuel cell favourable for vehicle drive. Vaste polymeer brandstofcel kansrijk voor voertuigaandrijving

    Energy Technology Data Exchange (ETDEWEB)

    Schmal, D. (Hoofdgroep Energie en Milieu TNO, Delft (Netherlands))

    1991-05-01

    A fuel cell drive equipped vehicle can lead to a reduction of the energy consumption and the emissions. However, fuel cells are still too large, too heavy and too expensive to be applicated in cars. Solid polymer fuel cells (SPFC) seem to offer the best prospects. A brief overview is given of developments in the fuel cell technology. Some demonstration programs and research activities in Europe are mentioned. 2 figs., 1 ill., 3 refs., 1 tab.

  8. Probing and Mapping Electrode Surfaces in Solid Oxide Fuel Cells

    Science.gov (United States)

    Blinn, Kevin S.; Li, Xiaxi; Liu, Mingfei; Bottomley, Lawrence A.; Liu, Meilin

    2012-01-01

    Solid oxide fuel cells (SOFCs) are potentially the most efficient and cost-effective solution to utilization of a wide variety of fuels beyond hydrogen 1-7. The performance of SOFCs and the rates of many chemical and energy transformation processes in energy storage and conversion devices in general are limited primarily by charge and mass transfer along electrode surfaces and across interfaces. Unfortunately, the mechanistic understanding of these processes is still lacking, due largely to the difficulty of characterizing these processes under in situ conditions. This knowledge gap is a chief obstacle to SOFC commercialization. The development of tools for probing and mapping surface chemistries relevant to electrode reactions is vital to unraveling the mechanisms of surface processes and to achieving rational design of new electrode materials for more efficient energy storage and conversion2. Among the relatively few in situ surface analysis methods, Raman spectroscopy can be performed even with high temperatures and harsh atmospheres, making it ideal for characterizing chemical processes relevant to SOFC anode performance and degradation8-12. It can also be used alongside electrochemical measurements, potentially allowing direct correlation of electrochemistry to surface chemistry in an operating cell. Proper in situ Raman mapping measurements would be useful for pin-pointing important anode reaction mechanisms because of its sensitivity to the relevant species, including anode performance degradation through carbon deposition8, 10, 13, 14 ("coking") and sulfur poisoning11, 15 and the manner in which surface modifications stave off this degradation16. The current work demonstrates significant progress towards this capability. In addition, the family of scanning probe microscopy (SPM) techniques provides a special approach to interrogate the electrode surface with nanoscale resolution. Besides the surface topography that is routinely collected by AFM and STM

  9. Ionic conductivity studies of solid oxide fuel cell electrolytes and theoretical modeling of an entire solid oxide fuel cell

    Science.gov (United States)

    Pornprasertsuk, Rojana

    Because of the steep increase in oil prices, the global warming effect and the drive for energy independence, alternative energy research has been encouraged worldwide. The sustainable fuels such as hydrogen, biofuel, natural gas, and solar energy have attracted the attention of researchers. To convert these fuels into a useful energy source, an energy conversion device is required. Fuel cells are one of the energy conversion devices which convert chemical potentials into electricity. Due to their high efficiency, the ease to scale from 1 W range to megawatts range, no recharging requirement and the lack of CO2 and NOx emission (if H2 and air/O 2 are used), fuel cells have become a potential candidate for both stationary power generators and portable applications. This thesis has been focused primarily on solid oxide fuel cell (SOFC) studies due to its high efficiency, varieties of fuel choices, and no water management problem. At the present, however, practical applications of SOFCs are limited by high operating temperatures that are needed to create the necessary oxide-ion vacancy mobility in the electrolyte and to create sufficient electrode reactivities. This thesis introduces several experimental and theoretical approaches to lower losses both in the electrolyte and the electrodes. Yttria stabilized zirconia (YSZ) is commonly used as a solid electrolyte for SOFCs due to its high oxygen-ion conductivity. To improve the ionic conductivity for low temperature applications, an approach that involves dilating the structure by irradiation and introducing edge dislocations into the electrolyte was studied. Secondly, to understand the activation loss in SOFC, the kinetic Monte Carlo (KMC) technique was implemented to model the SOFC operation to determining the rate-limiting step due to the electrodes on different sizes of Pt catalysts. The isotope exchange depth profiling technique was employed to investigate the irradiation effect on the ionic transport in different

  10. Hydrocarbon fuel processing of micro solid oxide fuel cell systems[Dissertation 17455

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M. J.

    2007-07-01

    The scope of this thesis is the numerical and experimental investigation of the fuel processing of a micro solid oxide fuel cell (SOFC) running on hydrocarbon fuel. The goal is to enhance the overall system efficiency by optimization of the reforming process in the steady state and the improvement of the start-up process. Micro SOFC are a potential alternative to the currently used batteries in portable devices. Liquid butane in a cartridge could be the energy source. This dissertation is focused on the fuel processing of the system, namely the reforming and post-combusting processes. The reformer converts the hydrocarbon fuel to a hydrogen rich gas that can be utilized by the SOFC. The post-combustor depletes the toxic and/or explosive gases before leaving the exhaust. Chapter One presents a short introduction to the field of hydrocarbon fuel processing in micro solid oxide fuel cell systems, the next three chapters deal with computational modeling of the transport phenomena inside a micro-reformer, which leads to a better understanding of the chemistry and the physics therein, hence progress in the design and operation parameters. The experimental part (i.e. Chapter Five) of this thesis focuses on the feasibility of a novel hybrid start-up method of a fuel cell system that employs existing components as an additional heat source. In Chapter Two the effect of wall heat conduction on the syngas (hydrogen and carbon monoxide) production of a micro-reformer, representing micro-fabricated channels or monoliths, is investigated. Methane is used as a model hydrocarbon fuel since its heterogeneous reaction path on rhodium is known and validated. The simulations demonstrate that the axial wall conduction strongly influences the performance of the micro-reformer and should not be neglected without a careful a priori investigation of its impact. Methane conversion and hydrogen yield are strongly dependent of the wall inner surface temperature, which is influenced by the

  11. Aqueous ammonium nitrate blasting composition containing solid carbonaceous fuel and method of preparing same

    Energy Technology Data Exchange (ETDEWEB)

    Sheeran, H.W.; Oriard, M.H.

    1969-06-17

    A blasting agent utilizes ammonium nitrate fuel and water to form a desired plasticity. The compound is detonatable because it employs fuel which is water stable either chemically or physically or both and remains in intimate association with the ammonium nitrate in the presence of water whether in the solid phase or liquid phase. The total oxygen balance of ammonium nitrate and fuel is adjusted by the formula proportions to be within detonatable limits. The method for making the blasting agent utilizes heat to liquefy a normally solid fuel while mixing with porous prilled ammonium nitrate to effect adsorption and absorption of the fuel by the ammonium nitrate. This effects intimate association in the solid phase and liberates only that portion of fuel into the liquid phase which corresponds to the quantity of ammonium nitrate which is dissolved by the added water. (19 claims)

  12. EPMA of interfaces applied to the solid oxide fuel cell.

    Science.gov (United States)

    Grübmeier, H; Naoumidis, A; Stochniol, G; Tsoga, A

    1995-10-01

    Chemical interactions at the phase boundaries of materials applied for the solid oxide fuel cell (SOFC) have been studied by EPMA. The chemical reactivity at the interface of La(y-x)Sr(x)MnO(3)/ZrO(2)-Y(2)O(3) is dependent on the stoichiometry (y) and the Sr content (x) of the perovskite. Typical reaction products (zirconates) and a diffusion zone in the ZrO(2)-Y(2)O(3) have been observed. The extension of cation release (Mn) is related to the increasing chemical activity of Mn oxide in the perovskite by the Sr substitution for La. The wettability of the metal/oxide interface in the anode cermet (Ni/ZrO(2)-Y(2)O(3)) has been found to be influenced by chemical reactions resulting from the applied reducing atmosphere with high carbon activity. The disintegration of ZrO(2)-Y(2)O(3) in contact with molten Ni or Ni-Ti and Ni-Cr alloys leads to the redeposition of Y(2)O(3)-enriched oxides and also to Zr-rich intermetallic compounds and eutectics.

  13. HIGH-TEMPERATURE TUBULAR SOLID OXIDE FUEL CELL GENERATOR DEVELOPMENT

    Energy Technology Data Exchange (ETDEWEB)

    S.E. Veyo

    1998-09-01

    During the Westinghouse/USDOE Cooperative Agreement period of November 1, 1990 through November 30, 1997, the Westinghouse solid oxide fuel cell has evolved from a 16 mm diameter, 50 cm length cell with a peak power of 1.27 watts/cm to the 22 mm diameter, 150 cm length dimensions of today's commercial prototype cell with a peak power of 1.40 watts/cm. Accompanying the increase in size and power density was the elimination of an expensive EVD step in the manufacturing process. Demonstrated performance of Westinghouse's tubular SOFC includes a lifetime cell test which ran for a period in excess of 69,000 hours, and a fully integrated 25 kWe-class system field test which operated for over 13,000 hours at 90% availability with less than 2% performance degradation over the entire period. Concluding the agreement period, a 100 kW SOFC system successfully passed its factory acceptance test in October 1997 and was delivered in November to its demonstration site in Westervoort, The Netherlands.

  14. Evaluation of solid fuel char briquettes from human waste.

    Science.gov (United States)

    Ward, Barbara J; Yacob, Tesfayohanes W; Montoya, Lupita D

    2014-08-19

    The developing world faces dual crises of escalating energy demand and lack of urban sanitation infrastructure that pose significant burdens on the environment. This article presents results of a study evaluating the feasibility of using human feces-derived char as a solid fuel for heating and cooking and a potential way to address both crises. The study determined the energy content and the elemental composition of chars pyrolyzed at 300, 450, and 750 °C. Fecal chars made at 300 °C were found to be similar in energy content to wood chars and bituminous coal, having a heating value of 25.6 ± 0.08 MJ/kg, while fecal chars made at 750 °C had an energy content of 13.8 ± 0.48 MJ/kg. The higher heating values of the studied chars were evaluated using their elemental composition and a published predictive model; results found good agreement between the measured and predicted values. Fecal chars made at low temperatures were briquetted with molasses/lime and starch binders. Briquettes made with 10% starch had an average impact resistance index of 79 and a higher heating value of 25 MJ/kg. These values are comparable to those of commercial charcoal briquettes, making fecal char briquettes a potential substitute that also contributes to the preservation of the environment.

  15. Strength of an electrolyte supported solid oxide fuel cell

    Science.gov (United States)

    Fleischhauer, Felix; Bermejo, Raul; Danzer, Robert; Mai, Andreas; Graule, Thomas; Kuebler, Jakob

    2015-11-01

    For the proper function of solid oxide fuel cells (SOFC) their structural integrity must be maintained during their whole lifetime. Any cell fracture would cause leakage and partial oxidization of the anode, leading to a reduced performance, if not catastrophic failure of the whole stack. In this study, the mechanical strength of a state of the art SOFC, developed and produced by Hexis AG/Switzerland, was investigated with respect to the influence of temperature and ageing, whilst for the anode side of the cell the strength was measured under reducing and oxidizing atmospheres. Ball-on-3-Ball bending strength tests and fractography conducted on anode and cathode half-cells revealed the underlying mechanisms, which lead to cell fracture. They were found to be different for the cathode and the anode side and that they change with temperature and ageing. Both anode and cathode sides exhibit the lowest strength at T = 850 °C, which is greatly reduced to the initial strength of the bare electrolyte. This reduction is the consequence of the formation of cracks in the electrode layer which either directly penetrate into the electrolyte (anode side) or locally increase the stress intensity level of pre-existing flaws of the electrolytes at the interface (cathode side).

  16. Development of improved cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, H.U.

    1991-03-01

    The University of Missouri-Rolla conducted a 17 month research program focused on the development and evaluation of improved cathode materials for solid oxide fuel cells (SOFC). The objectives of this program were: (1) the development of cathode materials of improved stability in reducing environments; and (2) the development of cathode materials with improved electrical conductivity. The program was successful in identifying some potential candidate materials: Air sinterable (La,Ca)(Cr,Co)O{sub 3} compositions were developed and found to be more stable than La{sub .8}Sr{sub .2}MnO{sub 3} towards reduction. Their conductivity at 1000{degrees}C ranged between 30 to 60 S/cm. Compositions within the (Y,Ca)(Cr,Co,Mn)O{sub 3} system were developed and found to have higher electrical conductivity than La{sub .8}Sr{sub .2}MnO{sub 3} and preliminary results suggest that their stability towards reduction is superior.

  17. Solid oxide fuels cells past present and future perspectives for SOFC technologies

    CERN Document Server

    Irvine, John TS

    2012-01-01

    Solid Oxide Fuel Cells (SOFCs) operate at high temperatures allowing more fuel flexibility and also useful heat output and so increase total efficiency, but does give some interesting engineering challenges. Solid Oxide Fuels Cells: Facts and Figures provides clear and accurate data for a selection of SOFC topics from the specific details of Ni cermet anodes, chemical expansion in materials, and the measuring and modelling of mechanical stresses, to the broader scope of the history and present design of cells, to SOFC systems and the future of SOFC. Celebrating Ulf Bossel s work on Solid Oxide

  18. Generation of transportation fuel from solid municipal waste plastics

    Energy Technology Data Exchange (ETDEWEB)

    Sarker, Moinuddin

    2010-09-15

    Transportation fuels derived from fossil fuels are subjected to the price fluctuations of the global marketplace, and constitute a major expense in the operation of a vehicle. Emissions from the evaporation and combustion of these fuels contribute to a range of environmental problems, causing poor air quality and emitting greenhouse gases that contribute to global warming. Alternative fuels created from domestic sources have been proposed as a solution to these problems, and many fuels are being developed based on biomass and other renewable sources. Natural State Research, Inc. developed different alternative hydrocarbon fuel which is produced from waste plastic materials.

  19. Combustion Characteristics of Chlorine-Free Solid Fuel Produced from Municipal Solid Waste by Hydrothermal Processing

    Directory of Open Access Journals (Sweden)

    Kunio Yoshikawa

    2012-11-01

    Full Text Available An experimental study on converting municipal solid waste (MSW into chlorine-free solid fuel using a combination of hydrothermal processing and water-washing has been performed. After the product was extracted from the reactor, water-washing experiments were then conducted to obtain chlorine-free products with less than 3000 ppm total chlorine content. A series of combustion experiments were then performed for the products before and after the washing process to determine the chlorine content in the exhaust gas and those left in the ash after the combustion process at a certain temperature. A series of thermogravimetric analyses were also conducted to compare the combustion characteristics of the products before and after the washing process. Due to the loss of ash and some volatile matter after washing process, there were increases in the fixed carbon content and the heating value of the product. Considering the possible chlorine emission, the washing process after the hydrothermal treatment should be necessary only if the furnace temperature is more than 800 °C.

  20. Plasma membranes modified by plasma treatment or deposition as solid electrolytes for potential application in solid alkaline fuel cells.

    Science.gov (United States)

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-07-30

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane.

  1. Plasma Membranes Modified by Plasma Treatment or Deposition as Solid Electrolytes for Potential Application in Solid Alkaline Fuel Cells

    Science.gov (United States)

    Reinholdt, Marc; Ilie, Alina; Roualdès, Stéphanie; Frugier, Jérémy; Schieda, Mauricio; Coutanceau, Christophe; Martemianov, Serguei; Flaud, Valérie; Beche, Eric; Durand, Jean

    2012-01-01

    In the highly competitive market of fuel cells, solid alkaline fuel cells using liquid fuel (such as cheap, non-toxic and non-valorized glycerol) and not requiring noble metal as catalyst seem quite promising. One of the main hurdles for emergence of such a technology is the development of a hydroxide-conducting membrane characterized by both high conductivity and low fuel permeability. Plasma treatments can enable to positively tune the main fuel cell membrane requirements. In this work, commercial ADP-Morgane® fluorinated polymer membranes and a new brand of cross-linked poly(aryl-ether) polymer membranes, named AMELI-32®, both containing quaternary ammonium functionalities, have been modified by argon plasma treatment or triallylamine-based plasma deposit. Under the concomitant etching/cross-linking/oxidation effects inherent to the plasma modification, transport properties (ionic exchange capacity, water uptake, ionic conductivity and fuel retention) of membranes have been improved. Consequently, using plasma modified ADP-Morgane® membrane as electrolyte in a solid alkaline fuel cell operating with glycerol as fuel has allowed increasing the maximum power density by a factor 3 when compared to the untreated membrane. PMID:24958295

  2. Comparison of coal/solid recovered fuel (SRF) with coal/refuse derived fuel (RDF) in a fluidized bed reactor.

    Science.gov (United States)

    Wagland, S T; Kilgallon, P; Coveney, R; Garg, A; Smith, R; Longhurst, P J; Pollard, S J T; Simms, N

    2011-06-01

    An experimental study was undertaken to compare the differences between municipal solid waste (MSW) derived solid recovered fuel (SRF) (complying with CEN standards) and refuse derived fuel (RDF). Both fuels were co-combusted with coal in a 50 kW fluidized bed combustor and the metal emissions were compared. Synthetic SRF was prepared in the laboratory by grinding major constituents of MSW such as paper, plastic, textile and wood. RDF was obtained from a local mechanical treatment plant. Heavy metal emissions in flue gas and ash samples from the (coal+10% SRF) fuel mixture were found to be within the acceptable range and were generally lower than that obtained for coal+10% RDF fuel mixture. The relative distribution of heavy metals in ash components and the flue gas stream shows the presence of a large fraction (up to 98%) of most of the metals in the ash (except Hg and As). Thermo-gravimetric (TG) analysis of SRF constituents was performed to understand the behaviour of fuel mixtures in the absence and presence of air. The results obtained from the experimental study will enhance the confidence of fuel users towards using MSW-derived SRF as an alternative fuel. Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.

  3. Micro Pulsed Inductive Thruster with Solid Fuel Option (uPIT_SF) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The Micro Pulsed Inductive Thruster with Solid Fuel Option (5PIT_SF) is a high-precision impulse bit electromagnetic plasma micro-thruster. The 5PIT prototype is a...

  4. Fuel cells with solid polymer electrolyte and their application on vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Fateev, V.

    1996-04-01

    In Russia, solid polymer electrolyte MF-4-SK has been developed for fuel cells. This electrolyte is based on perfluorinated polymer with functional sulfogroups. Investigations on electrolyte properties and electrocatalysts have been carried out.

  5. Solid waste from Swine wastewater as a fuel source for heat production

    National Research Council Canada - National Science Library

    Park, Myung-Ho; Kumar, Sanjay; Ra, ChangSix

    2012-01-01

    This study was to evaluate the feasibility of recycling the solids separated from swine wastewater treatment process as a fuel source for heat production and to provide a data set on the gas emissions...

  6. Mutagenicity and Pollutant Emission Factors of Solid-Fuel Cookstoves: Comparison with Other Combustion Sources

    National Research Council Canada - National Science Library

    Mutlu, Esra; Warren, Sarah H; Ebersviller, Seth M; Kooter, Ingeborg M; Schmid, Judith E; Dye, Janice A; Linak, William P; Gilmour, M Ian; Jetter, James J; Higuchi, Mark; DeMarini, David M

    2016-01-01

    .... We evaluated two categories of solid-fuel cookstoves for eight pollutant and four mutagenicity emission factors, correlated the mutagenicity emission factors, and compared them to those of other combustion emissions...

  7. Lanthanum manganate based cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Juhl Joergensen, M.

    2001-07-01

    Composite cathodes for solid oxide fuel cells were investigated using electrochemical impedance spectroscopy and scanning electron microscopy. The aim was to study the oxygen reduction process in the electrode in order to minimise the voltage drop in the cathode. The electrodes contained a composite layer made from lanthanum strontium manganate (LSM) and yttria stabilised zirconia (YSZ) and a layer of pure LSM aimed for current collection. The performance of the composite electrodes was sensitive to microstructure and thickness. Further, the interface between the composite and the current collecting layer proved to affect the performance. In a durability study severe deg-radation of the composite electrodes was found when passing current through the electrode for 2000 hours at 1000 deg. C. This was ascribed to pore formation along the composite interfaces and densification of the composite and current collector microstructure. An evaluation of the measurement approach indicated that impedance spectroscopy is a very sensitive method. This affects the reproducibility, as small undesirable variations in for instance the microstructure from electrode to electrode may change the impedance. At least five processes were found to affect the impedance of LSM/YSZ composite electrodes. Two high frequency processes were ascribed to transport of oxide ions/oxygen intermediates across LSM/YSZ interfaces and through YSZ in the composite. Several competitive elementary reaction steps, which appear as one medium frequency process in the impedance spectra, were observed. A low frequency arc related to gas diffusion limitation in a stagnant gas layer above the composite structure was detected. Finally, an inductive process, assumed to be connected to an activation process involving segregates at the triple phase boundary between electrode, electrolyte and gas phase, was found. (au)

  8. Alternative anode materials for methane oxidation in solid oxide fuel cells

    OpenAIRE

    Sfeir, Joseph; Grätzel, Michael

    2005-01-01

    Fuel Cells are electrochemical devices that are able to directly convert chemical energy to electrical energy, without any Carnot limitation. Hence, their energy efficiencies are relatively high. Among the various types of fuel cells, solid oxide fuel cells (SOFC) are operated at high temperatures and in principle can run on various fuels such as natural gas and hydrogen. As natural gas is sought to become one of the main fuels of the next decades, its direct feed to a SOFC is desirable as th...

  9. Formulation and Testing of Paraffin-Based Solid Fuels Containing Energetic Additives for Hybrid Rockets

    Science.gov (United States)

    Larson, Daniel B.; Boyer, Eric; Wachs,Trevor; Kuo, Kenneth K.; Story, George

    2012-01-01

    Many approaches have been considered in an effort to improve the regression rate of solid fuels for hybrid rocket applications. One promising method is to use a fuel with a fast burning rate such as paraffin wax; however, additional performance increases to the fuel regression rate are necessary to make the fuel a viable candidate to replace current launch propulsion systems. The addition of energetic and/or nano-sized particles is one way to increase mass-burning rates of the solid fuels and increase the overall performance of the hybrid rocket motor.1,2 Several paraffin-based fuel grains with various energetic additives (e.g., lithium aluminum hydride (LiAlH4) have been cast in an attempt to improve regression rates. There are two major advantages to introducing LiAlH4 additive into the solid fuel matrix: 1) the increased characteristic velocity, 2) decreased dependency of Isp on oxidizer-to-fuel ratio. The testing and characterization of these solid-fuel grains have shown that continued work is necessary to eliminate unburned/unreacted fuel in downstream sections of the test apparatus.3 Changes to the fuel matrix include higher melting point wax and smaller energetic additive particles. The reduction in particle size through various methods can result in more homogeneous grain structure. The higher melting point wax can serve to reduce the melt-layer thickness, allowing the LiAlH4 particles to react closer to the burning surface, thus increasing the heat feedback rate and fuel regression rate. In addition to the formulation of LiAlH4 and paraffin wax solid-fuel grains, liquid additives of triethylaluminum and diisobutylaluminum hydride will be included in this study. Another promising fuel formulation consideration is to incorporate a small percentage of RDX as an additive to paraffin. A novel casting technique will be used by dissolving RDX in a solvent to crystallize the energetic additive. After dissolving the RDX in a solvent chosen for its compatibility

  10. Study of catalysis for solid oxide fuel cells and direct methanol fuel cells

    Science.gov (United States)

    Jiang, Xirong

    Fuel cells offer the enticing promise of cleaner electricity with lower environmental impact than traditional energy conversion technologies. Driven by the interest in power sources for portable electronics, and distributed generation and automotive propulsion markets, active development efforts in the technologies of both solid oxide fuel cell (SOFC) and direct methanol fuel cell (DMFC) devices have achieved significant progress. However, current catalysts for fuel cells are either of low catalytic activity or extremely expensive, presenting a key barrier toward the widespread commercialization of fuel cell devices. In this thesis work, atomic layer deposition (ALD), a novel thin film deposition technique, was employed to apply catalytic Pt to SOFC, and investigate both Pt skin catalysts and Pt-Ru catalysts for methanol oxidation, a very important reaction for DMFC, to increase the activity and utilization levels of the catalysts while simultaneously reducing the catalyst loading. For SOFCs, we explored the use of ALD for the fabrication of electrode components, including an ultra-thin Pt film for use as the electrocatalyst, and a Pt mesh structure for a current collector for SOFCs, aiming for precise control over the catalyst loading and catalyst geometry, and enhancement in the current collect efficiency. We choose Pt since it has high chemical stability and excellent catalytic activity for the O2 reduction reaction and the H2 oxidation reaction even at low operating temperatures. Working SOFC fuel cells were fabricated with ALD-deposited Pt thin films as an electrode/catalyst layer. The measured fuel cell performance reveals that comparable peak power densities were achieved for ALD-deposited Pt anodes with only one-fifth of the Pt loading relative to a DC-sputtered counterpart. In addition to the continuous electrocatalyst layer, a micro-patterned Pt structure was developed via the technique of area selective ALD. By coating yttria-stabilized zirconia, a

  11. Development of metal supported Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez-Martinez, L. M.; Alava, I.; Antepara, I.; Castro, U.; Diez-Linaza, E.; Lecanda, N.; Montero, X.; Rivas, M.; Villarreal, I.; Laresgoiti, A.

    2005-07-01

    Metal supported solid oxide fuel cells have been developed by Ikerlan in collaboration with Lawrence Berkeley National Laboratory, as a promising way to reduce materials costs. This, in conjunction with cost-effective processing techniques, is vital for successful commercialisation of SOFC's. In this type of cells, the Ni/YSZ support anode has been replaced by a porous stainless steel support structure, and the Ni/YSZ anode is now limited to a thin catalytically active layer. The basic structure also includes a thin, 5-15 micron YSZ electrolyte and a cathode (LSF, LSCF or similar) of approximately 15-20 microns. This robust metal structure provides both high thermal and electronic conductivity, improves thermal shock resistance and allows for simple, cost effective sealing strategies. Metal supported SOFC technology, first patented in 1966 [1], has only recently received interest but the majority of current research is centred on relatively expensive fabrication techniques such as plasma spray [2] and metalorganic chemical vapour deposition [3]. Ceres Power [4,5] has, conversely, focused on the integration of low cost ceramic processes with metallic materials to develop doped ceria based electrolyte metal supported planar cells operating at 500-600C. Ikerlan, as part of Mondragon Corporacion Cooperativa (MCC), aims to develop metal supported SOFC tubular systems for small stationary applications based on natural gas, propane and similar fuels. The target temperature for operation is 700C, although studies are performed over a wider, 650-800C temperature range. Conventional low-cost processing and coating technologies, such as colloidal spray, dip coating and tape casting, are used to fabricate cofired ferritic supports, anodes and thin electrolytes under reducing atmospheres. The cathode is subsequently deposited and fired in air at temperatures below 1100C. The cofiring process adds several challenging requirements on the properties of the materials

  12. Functionally Graded Cathodes for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    YongMan Choi; Meilin Liu

    2006-09-30

    This DOE SECA project focused on both experimental and theoretical understanding of oxygen reduction processes in a porous mixed-conducting cathode in a solid oxide fuel cell (SOFC). Elucidation of the detailed oxygen reduction mechanism, especially the rate-limiting step(s), is critical to the development of low-temperature SOFCs (400 C to 700 C) and to cost reduction since much less expensive materials may be used for cell components. However, cell performance at low temperatures is limited primarily by the interfacial polarization resistances, specifically by those associated with oxygen reduction at the cathode, including transport of oxygen gas through the porous cathode, the adsorption of oxygen onto the cathode surface, the reduction and dissociation of the oxygen molecule (O{sub 2}) into the oxygen ion (O{sup 2-}), and the incorporation of the oxygen ion into the electrolyte. In order to most effectively enhance the performance of the cathode at low temperatures, we must understand the mechanism and kinetics of the elementary processes at the interfaces. Under the support of this DOE SECA project, our accomplishments included: (1) Experimental determination of the rate-limiting step in the oxygen reduction mechanism at the cathode using in situ FTIR and Raman spectroscopy, including surface- and tip-enhanced Raman spectroscopy (SERS and TERS). (2) Fabrication and testing of micro-patterned cathodes to compare the relative activity of the TPB to the rest of the cathode surface. (3) Construction of a mathematical model to predict cathode performance based on different geometries and microstructures and analyze the kinetics of oxygen-reduction reactions occurring at charged mixed ionic-electronic conductors (MIECs) using two-dimensional finite volume models with ab initio calculations. (4) Fabrication of cathodes that are graded in composition and microstructure to generate large amounts of active surface area near the cathode/electrolyte interface using a

  13. Effect of Composting Parameters on the Power Performance of Solid Microbial Fuel Cells

    OpenAIRE

    Chin-Tsan Wang; Yao-Cheng Lee; Fan-Ying Liao

    2015-01-01

    Nowadays, solid organic waste is of major environmental concern and is reaching critical levels worldwide. Currently, a form of natural decomposition, known as composting technology, is widely used to deal with organic waste. This method is applied to enhance the performance of solid microbial fuel cells (SMFCs) in this study. Operational composting parameters (carbon/nitrogen ratio, moisture content and pH value) are investigated to explore the optimal power performance of solid microbial fu...

  14. New Cathode Materials for Intermediate Temperature Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Allan J. Jacobson

    2006-09-30

    the perovskite compositions that were being investigated at PNNL, in order to assess the relative importance of the intrinsic properties such as oxygen ion diffusion and surface exchange rates as predictors of performance in cell tests. We then used these measurements to select new materials for scaled up synthesis and performance evaluation in single cell tests. The results of the single cell tests than provided feedback to the materials synthesis and selection steps. In this summary, the following studies are reported: (1) Synthesis, characterization, and DC conductivity measurements of the P1 compositions La{sub 0.8}Sr{sub 0.2}FeO{sub 3-x} and La{sub 0.7}Sr{sub 0.3}FeO{sub 3-x} were completed. A combinational approach for preparing a range P1 (La,Sr)FeO{sub 3} compositions as thin films was investigated. Synthesis and heat treatment of amorphous SrFeO{sub 3-x} and LaFeO{sub 3-x} films prepared by pulsed laser deposition are described. (2) Oxygen transport properties of K1 compositions La{sub x}Pr{sub 2-x}NiO{sub 4+d} (x =2.0, 1.9, 1.2, 1.0 and 0) measured by electrical conductivity relaxation are presented in this report. Area specific resistances determined by ac impedance measurements for La{sub 2}NiO{sub 4+{delta}} and Pr{sub 2}NiO{sub 4+{delta}} on CGO are encouraging and suggest that further optimization of the electrode microstructure will enable the target to be reached. (3) The oxygen exchange kinetics of the oxygen deficient double perovskite LnBaCo{sub 2}O{sub 5.5+{delta}} (Ln=Pr and Nd) were determined by electrical conductivity relaxation. The high electronic conductivity and rapid diffusion and surface exchange kinetics of PBCO suggest its application as cathode material in intermediate temperature solid oxide fuel cells. The first complete cell measurements were performed on Ni/CGO/CGO/PBCO/CGO cells. (4) The oxygen exchange kinetics of highly epitaxial thin films of PrBaCo{sub 2}O{sub 5.5+{delta}} (PBCO) has been determined by electrical conductivity

  15. Thermal Analysis of Solid Fuels in an Inert Atmosphere

    Science.gov (United States)

    Kijo-Kleczkowska, Agnieszka; Szumera, Magdalena; Środa, Katarzyna

    2017-12-01

    The paper takes the analysis of thermal studies of different types of fuels. It allowed diversification of fuels depending on their composition and origin. Consideration of coal, biomass and waste (coal mule, sewage sludge) as fuel is nowadays an important aspect of energy in our country. It should be emphasized that Poland power engineering is based up to 95% on coal - the primary fuel. Mining industry, forced to deliver power engineering more and better fuel, must however, use a deeper cleaning of coal. This results in a continuous increase waste in the form of mule flotation. The best method of disposing these mule is combustion and co-combustion with other fuels. On the other hand, commonly increasing awareness state of the environment and the need to reduce CO2 emissions energy industry have committed to implement alternative solutions in order to gain power, through, i.a.: development technologies use of biomass, which is one of the most promising renewable energy sources in Poland. The paper presents the results of research TG-DTA fuels made in an inert atmosphere.

  16. Solid alkaline membrane fuel cell : what are they advantages and drawbacks compared to proton exchange membrane fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Coutanceau, C.; Baranton, S.; Simoes, M. [Univ. de Poitiers, Poitiers (France). Laboratoire de Catalyse en Chimie Organique, UMR CNRS

    2010-07-01

    Low temperature fuel cells such as proton exchange membrane fuel cells (PEMFCs) and direct alcohol fuel cells (DAFCs) are promising power sources for portable electronics and transportation applications. However, these fuel cells require high amounts of platinum at the anodes to achieve high cell performance. Although alkaline membrane fuel cells (AFCs) may be an alternative to PEMFCs, the technology of low temperature fuel cells is less developed than that of fuel cells working with a solid acid electrolyte. Interest in solid alkaline membrane fuel cells (SAMFCs) has increased in recent years because it is easier to activate the oxidation and reduction reactions in alkaline medium than in acidic medium. Fewer platinum based catalysts are needed due to higher electrode kinetics. The development of hydroxyl conductive membrane makes this technology available, but the fuel to be used in the system must be considered. Pure hydrogen or hydrogen-rich gases offer high electric efficiency, but their production, storage, and distribution are not sufficient for a large-scale development. This paper discussed the relatively good electroreactivity of polyols such as glycerol and ethylene glycol in a SAMFC, as well as sodium borohydride (NaBH{sub 4}) as an alternative. The working principle of SAMFCs was also presented along with considerations regarding the electrochemical reactions occurring at the electrodes, and requirements concerning the catalysts, the triple phase boundary in the electrode and the anionic membrane. Palladium based catalysts were found to be an interesting alternative to platinum in SAMFCs. In situ FTIR measurements and oxidation products analysis was used to determine the electrooxidation pathways of alcohol and NaBH{sub 4}in alkaline medium. The study also included a comparison with oxidation mechanisms in acid medium. 8 refs.

  17. Potential electrode materials for symmetrical Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ruiz Morales, J. C.

    2008-08-01

    Full Text Available Chromites, titanates and Pt-YSZ-CeO2 cermets have been investigated as potential electrode materials for an alternative concept of Solid Oxide Fuel Cell (SOFC, the symmetrical SOFCs (SFC. In this configuration, the same electrode material is used simultaneously as anode and cathode. Interconnector materials, such as chromites, could be considered as potential SFC electrodes, at least under pure hydrogen-fed at relatively high temperatures, as they do not exhibit significant catalytic activity towards hydrocarbon oxidation. This may be overcome by partially substituting Cr in the perovskite B-sites by other transition metal cations such as Mn. La0.75Sr0.25Cr0.5Mn0.5O3-δ (LSCM is a good candidate for such SFCs, rendering fuel cell performances in excess of 500 and 300mW/cm2 using pure H2 and CH4 as fuel, at 950 oC. Similarly, typical n-type electronic conductors traditionally regarded as anode materials, such as strontium titanates, may also operate under oxidising conditions as cathodes by substituting some Ti content for Fe to introduce p-type conductivity. Preliminary electrochemical experiments on La4Sr8Ti12-xFexO38-δ-based SFCs show that they perform reasonably well under humidified H2, at high temperatures. A third group of materials is the support material of any typical cermet anode, i.e. YSZ, CeO2 plus a current collector. It has been found that this combination could be optimised to operate as SFC electrodes, rendering performances of 400mW/cm2 under humidified pure H2 at 950oC.

    Cromitas, titanatos y cermets de Pt-YSZ-CeO2 han sido investigados como potenciales materiales de electrodo para un concepto alternativo de Pilas de Combustible de Óxidos Sólidos (SOFC, las pilas SOFC simétricas (SFC. En

  18. Planar Solid-Oxide Fuel Cell Research and Development

    Science.gov (United States)

    2013-03-28

    electrolyte membrane ( PEM ) fuel cells ", Applied Surface Sei., 227 (2004) 56-72. [10] Grujicic, M., and Chittajallu, K. M., "Optimization of the...cathode geometry in polymer electrolyte membrane ( PEM ) fuel cells ", Chem. Eng. Sei., 59 (2004) 5883-5895. 36 [11] Anderson, W.K., Newman, J.C., Whitfield...M., Djilali, N, Suleman, A., "Optimization of a planar self-breathing PEM fuel cell cathode", AIAA 2006-6917, 11th AIAA/ISSMO Multidisciplinary

  19. Sulfur Poisoning of the Water Gas Shift Reaction on Anode Supported Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Hagen, Anke

    2013-01-01

    resistance increased both in the high and low frequency region, which indicates a strong poisoning of the water gas shift reaction and thus a lack of hydrogen fuel in addition to the poisoning of the electrochemical hydrogen oxidation. All poisoning effects are reversible under the applied operating......Investigation of fuels containing sulfur impurities is important regarding durability of solid oxide fuel cells (SOFC) because they are present in various potential fuels for SOFC applications. The effect of H2S in the ppm range on the performance of state-of-the-art anode supported SOFC at 850...

  20. Generation and Solid Oxide Fuel Cell Carbon Sequestration in Northwest Indiana

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Peavey; Norm Bessette

    2007-09-30

    The objective of the project is to develop the technology capable of capturing all carbon monoxide and carbon dioxide from natural gas fueled Solid Oxide Fuel Cell (SOFC) system. In addition, the technology to electrochemically oxidize any remaining carbon monoxide to carbon dioxide will be developed. Success of this R&D program would allow for the generation of electrical power and thermal power from a fossil fuel driven SOFC system without the carbon emissions resulting from any other fossil fueled power generationg system.

  1. Methane steam reforming kinetics over Ni-YSZ anode materials for Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Mogensen, David

    Solid Oxide Fuel Cells (SOFC) is a technology with great potential. Its high efficiency makes it a relevant alternative to existing technologies for utilizing fossil fuels and its fuel versatility makes it invaluable in the transition from a fossil fuel based energy system to on based on renewable...... of internal reforming has to be carefully controlled. The objective of this thesis is to make such a careful control possible by examining the rate of internal steam reforming in SOFCs. The catalytic steam reforming activity of Ni-YSZ anode material was tested both in a packed bed reactor to determine...

  2. A Direct Methane Solid Oxide Fuel Cell (DMSOFC) Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Producing return fuel on Mars rather than carrying it from Earth significantly reduces the mass that must be lifted from Earth for a manned mission to Mars. The most...

  3. High Efficiency Direct Methane Solid Oxide Fuel Cell System Project

    Data.gov (United States)

    National Aeronautics and Space Administration — NASA has a defined need for energy dense and highly efficient energy storage and power delivery systems for future space missions. Compared to other fuel cell...

  4. Selected aspects of the design and diagnostics of solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Lis Bartłomiej

    2016-01-01

    Full Text Available An increased growth in demand for energy accompanied by efforts to limit its negative impact on the environment is forcing society to seek new, more efficient energy sources. Fuel cells are one of the most promising solutions among the widely developed new generation of electrical generators. Fuel cells directly convert chemical fuel into electricity. Water and waste heat are by-products of fuel cell operation. Solid oxide fuel cells (SOFCs have proven to be one of the most interesting solutions among the five types of technologically advanced fuel cells, for their ability to operate at temperatures above 800°C. Furthermore, SOFCs are characterized by other advantages in comparison to PEMFCs, including: (1 no need to use expensive catalysts (e.g. platinum, the price of which is high, and its resources limited, (2 the possibility of direct, internal conversion of hydrocarbon fuels, (3 lower sensitivity to contaminants (in particular, hydrogen fuel containing CO, which is useful for SOFCs instead of the platinum catalyst poisoners, and (4 the possibility of using waste heat in a gas turbine, or for heating or other industrial purposes. The paper discusses selected issues regarding the construction and characteristics of planar solid oxide fuel cells. Selected results of the following electrochemical investigations: Ba0.9Ca0.1Ce0.9Y0.1O3-based proton electrolyte as possible components of SOFCs operating at intermediate temperature range (500-700°C.

  5. Cerium-modified doped strontium titanate compositions for solid oxide fuel cell anodes and electrodes for other electrochemical devices

    Science.gov (United States)

    Marina, Olga A [Richland, WA; Stevenson, Jeffry W [Richland, WA

    2010-03-02

    The present invention provides novel compositions that find advantageous use in making electrodes for electrochemical cells and electrochemical devices such as solid oxide fuel cells, electrolyzers, sensors, pumps and the like, the compositions comprising cerium-modified doped strontium titanate. The invention also provides novel methods for making and using anode material compositions and solid oxide fuel cells and solid oxide fuel cell assemblies having anodes comprising the compositions.

  6. Copper-substituted perovskite compositions for solid oxide fuel cell cathodes and oxygen reduction electrodes in other electrochemical devices

    Science.gov (United States)

    Rieke, Peter C [Pasco, WA; Coffey, Gregory W [Richland, WA; Pederson, Larry R [Kennewick, WA; Marina, Olga A [Richland, WA; Hardy, John S [Richland, WA; Singh, Prabhaker [Richland, WA; Thomsen, Edwin C [Richland, WA

    2010-07-20

    The present invention provides novel compositions that find advantageous use in making electrodes for electrochemical cells. Also provided are electrochemical devices that include active oxygen reduction electrodes, such as solid oxide fuel cells, sensors, pumps and the like. The compositions comprises a copper-substituted ferrite perovskite material. The invention also provides novel methods for making and using the electrode compositions and solid oxide fuel cells and solid oxide fuel cell assemblies having cathodes comprising the compositions.

  7. Development of Ni-Ba(Zr,Y)O3 cermet anodes for direct ammonia-fueled solid oxide fuel cells

    Science.gov (United States)

    Miyazaki, Kazunari; Okanishi, Takeou; Muroyama, Hiroki; Matsui, Toshiaki; Eguchi, Koichi

    2017-10-01

    In this study, the availability of Ni-Ba(Zr,Y)O3-δ (BZY) cermet for the anode of direct ammonia-fueled solid oxide fuel cells (SOFCs) is evaluated. In this device, the anodes need to be active for the catalytic ammonia decomposition as well as the electrochemical hydrogen oxidation. In the catalytic activity test, ammonia decomposes completely over Ni-BZY at ca. 600 °C, while higher temperature is required to accomplish the complete decomposition over the conventional SOFC anode of Ni-yttria-stabilized zirconia cermet. The high activity of Ni-BZY is attributed to the high basicity of BZY and the high resistance to hydrogen poisoning effect. The electrochemical property of Ni-BZY anode is also evaluated with the anode-supported cell of Ni-BZY|BZY|Pt at 600-700 °C with feeding ammonia or hydrogen as a fuel. Since the residence time of ammonia fuel in the thick Ni-BZY anode is long, the difference in the cell performance between two fuels is relatively small. Furthermore, it is proved that the steam concentration in the fuel strongly affects the cell performance. We find that this factor is important to satisfy the above mentioned requirements for the anode of direct ammonia-fueled SOFCs. Throughout this study, it is concluded that Ni-BZY cermet will be a promising anode.

  8. Modeling the burnout of solid polydisperse fuel under the conditions of external heat transfer

    Science.gov (United States)

    Skorik, I. A.; Goldobin, Yu. M.; Tolmachev, E. M.; Gal'perin, L. G.

    2013-11-01

    A self-similar burnout mode of solid polydisperse fuel is considered taking into consideration heat transfer between fuel particles, gases, and combustion chamber walls. A polydisperse composition of fuel is taken into account by introducing particle distribution functions by radiuses obtained for the kinetic and diffusion combustion modes. Equations for calculating the temperatures of particles and gases are presented, which are written for particles average with respect to their distribution functions by radiuses taking into account the fuel burnout ratio. The proposed equations take into consideration the influence of fuel composition, air excess factor, and gas recirculation ratio. Calculated graphs depicting the variation of particle and gas temperatures, and the fuel burnout ratio are presented for an anthracite-fired boiler.

  9. High-Temperature Chemistry in Solid Oxide Fuel Cells: In Situ Optical Studies.

    Science.gov (United States)

    Pomfret, Michael B; Walker, Robert A; Owrutsky, Jeffrey C

    2012-10-18

    Solid oxide fuels cells (SOFCs) are promising devices for versatile and efficient power generation with fuel flexibility, but their viability is contingent upon understanding chemical and material processes to improve their performance and durability. Newly developed in situ optical methods provide new insight into how carbon deposition varies with different hydrocarbon and alcohol fuels and depends on operating conditions. Some findings, such as heavier hydrocarbon fuels forming more carbon than lighter fuels, are expected, but other discoveries are surprising. For example, methanol shows a greater tendency to form carbon deposits than methane at temperatures below 800 °C, and kinetically controlled steam reforming with ethanol at high temperatures (∼800 °C) is less detrimental to SOFC performance than operating the device with dry methanol as the fuel. In situ optical techniques will continue to provide the chemical information and mechanistic insight that is critical for SOFCs to become a viable energy conversion technology.

  10. System modeling of an air-independent solid oxide fuel cell system for unmanned undersea vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Burke, A. Alan; Carreiro, Louis G. [Naval Undersea Warfare Center, Division Newport, 1176 Howell Street, Bldg. 1302/2, Newport, RI 02841 (United States)

    2006-07-14

    To examine the feasibility of a solid oxide fuel cell (SOFC)-powered unmanned undersea vehicle (UUV), a system level analysis is presented that projects a possible integration of the SOFC stack, fuel steam reformer, fuel/oxidant storage and balance of plant components into a 21-in. diameter UUV platform. Heavy hydrocarbon fuel (dodecane) and liquid oxygen (LOX) are chosen as the preferred reactants. A maximum efficiency of 45% based on the lower heating value of dodecane was calculated for a system that provides 2.5kW for 40h. Heat sources and sinks have been coupled to show viable means of thermal management. The critical design issues involve proper recycling of exhaust steam from the fuel cell back into the reformer and effective use of the SOFC stack radiant heat for steam reformation of the hydrocarbon fuel. (author)

  11. Electroplating of Protective Coatings on Interconnects Used for Solid Oxide Fuel Cell Stacks

    DEFF Research Database (Denmark)

    Harthøj, Anders

    , are they can utilize a wide range of fuels, e.g. hydrogen, natural gas and methanol, do not contain noble metals and have a high efficiency. A major obstacle to the commercialization of SOFC technology is the high degradation rates and costs of the systems. A significant source of degradation is high......Solid oxide fuel Cell (SOFC) technology can with a high efficiency produce environmentally clean electricity by converting the chemical energy in a fuel to electrical energy. SOFC systems have a high operation temperature, approx. 600-850 °C. Advantages compared to other types of fuel cells...... temperature corrosion of the so called interconnects, which consists of high chromium ferritic steel. In an SOFC stack, interconnects connects the individual fuel cells electrically and mechanically. An interconnect is exposed to a dual atmosphere, with air on the side facing the SOFC cathode and fuel...

  12. Plant Performance of Solid Oxide Fuel Cell Systems Fed by Alternative Fuels

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2016-01-01

    Different plant design for several fuel types such as natural gas, methanol, ethanol, DME, ammonia and pure hydrogen are presented and analysed. Anode recirculation which is an important issue in SOFC plants are also explored and studied. It is shown that depending on type of the fuel whether fuel...... recycle increases plant efficiency only if fuel utilization factor is low. Other important issues such as why plant efficiency is lower when it is fed with hydrogen or biogas compared to when it is fed by other fuels such as methanol, ethanol, DME and ammonia will also be discussed and explained...... recirculation is needed or not and if so then what would be the effect of anode recycling on plant efficiency. A single study with similar conditions and prerequisites will thus reveal the importance of fuel recirculation on plant performance with alternative fuels. It is also shown that increasing anode...

  13. Municipal solid waste combustion: Fuel testing and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Bushnell, D.J.; Canova, J.H.; Dadkhah-Nikoo, A.

    1990-10-01

    The objective of this study is to screen and characterize potential biomass fuels from waste streams. This will be accomplished by determining the types of pollutants produced while burning selected municipal waste, i.e., commercial mixed waste paper residential (curbside) mixed waste paper, and refuse derived fuel. These materials will be fired alone and in combination with wood, equal parts by weight. The data from these experiments could be utilized to size pollution control equipment required to meet emission standards. This document provides detailed descriptions of the testing methods and evaluation procedures used in the combustion testing and characterization project. The fuel samples will be examined thoroughly from the raw form to the exhaust emissions produced during the combustion test of a densified sample.

  14. Perovskite solid electrolytes: Structure, transport properties and fuel cell applications

    DEFF Research Database (Denmark)

    Bonanos, N.; Knight, K.S.; Ellis, B.

    1995-01-01

    Doped barium cerate perovskites, first investigated by Iwahara and co-workers, have ionic conductivities of the order of 20 mS/cm at 800 degrees C making them attractive as fuel cell electrolytes for this temperature region. They have been used to construct laboratory scale fuel cells, which...... vapour transfer in a cell in which the perovskite is exposed to wet hydrogen on both sides. The evolution of transport properties with temperature is discussed in relation to structure. Neutron diffraction studies of doped and undoped barium cerate are reported, revealing a series of phase transitions...

  15. Child mortality from solid-fuel use in India: a nationally-representative case-control study

    Directory of Open Access Journals (Sweden)

    Bassani Diego G

    2010-08-01

    Full Text Available Abstract Background Most households in low and middle income countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India. Methods We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609 601 living children living in 1.1 million nationally-representative homes in India. Analyses were stratified by child's gender, age (neonatal, post-neonatal, 1-4 years and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias. Results Solid fuel use was very common (87% in households with child deaths and 77% in households with living children. After adjustment for demographic factors and living conditions, solid-fuel use significantly increase child deaths at ages 1-4 (prevalence ratio (PR boys: 1.30, 95%CI 1.08-1.56; girls: 1.33, 95%CI 1.12-1.58. More girls than boys died from exposure to solid fuels. Solid fuel use was also associated with non-fatal pneumonia (boys: PR 1.54 95%CI 1.01-2.35; girls: PR 1.94 95%CI 1.13-3.33. Conclusions Child mortality risks, from all causes, due to solid fuel exposure were lower than previously, but as exposure was common solid, fuel caused 6% of all deaths at ages 0-4, 20% of deaths at ages 1-4 or 128 000 child deaths in India in 2004. Solid fuel use has declined only modestly in the last decade. Aside from reducing exposure, complementary strategies such as immunization and treatment could also reduce child mortality from acute respiratory infections.

  16. Child mortality from solid-fuel use in India: a nationally-representative case-control study - article no. 491

    Energy Technology Data Exchange (ETDEWEB)

    Bassani, D.G.; Jha, P.; Dhingra, N.; Kumar, R. [St. Michaels Hospital, Toronto, ON (Canada)

    2010-08-17

    Most households in low and middle income countries, including in India, use solid fuels (coal/coke/lignite, firewood, dung, and crop residue) for cooking and heating. Such fuels increase child mortality, chiefly from acute respiratory infection. There are, however, few direct estimates of the impact of solid fuel on child mortality in India. Methods: We compared household solid fuel use in 1998 between 6790 child deaths, from all causes, in the previous year and 609 601 living children living in 1.1 million nationally-representative homes in India. Analyses were stratified by child's gender, age (neonatal, post-neonatal, 1-4 years) and colder versus warmer states. We also examined the association of solid fuel to non-fatal pneumonias. Solid fuel use was very common (87% in households with child deaths and 77% in households with living children). After adjustment for demographic factors and living conditions, solid-fuel use significantly increase child deaths at ages 1-4 (prevalence ratio (PR) boys: 1.30, 95%CI 1.08-1.56; girls: 1.33, 95%CI 1.12-1.58). More girls than boys died from exposure to solid fuels. Solid fuel use was also associated with non-fatal pneumonia (boys: PR 1.54 95%CI 1.01-2.35; girls: PR 1.94 95%CI 1.13-3.33). Child mortality risks, from all causes, due to solid fuel exposure were lower than previously, but as exposure was common solid, fuel caused 6% of all deaths at ages 0-4, 20% of deaths at ages 1-4 or 128 000 child deaths in India in 2004. Solid fuel use has declined only modestly in the last decade. Aside from reducing exposure, complementary strategies such as immunization and treatment could also reduce child mortality from acute respiratory infections.

  17. Aqueous liquid feed organic fuel cell using solid polymer electrolyte membrane

    Science.gov (United States)

    Surampudi, Subbarao (Inventor); Narayanan, Sekharipuram R. (Inventor); Vamos, Eugene (Inventor); Frank, Harvey A. (Inventor); Halpert, Gerald (Inventor); Olah, George A. (Inventor); Prakash, G. K. Surya (Inventor)

    1997-01-01

    A liquid organic fuel cell is provided which employs a solid electrolyte membrane. An organic fuel, such as a methanol/water mixture, is circulated past an anode of a cell while oxygen or air is circulated past a cathode of the cell. The cell solid electrolyte membrane is preferably fabricated from Nafion.TM.. Additionally, a method for improving the performance of carbon electrode structures for use in organic fuel cells is provided wherein a high surface-area carbon particle/Teflon.TM.-binder structure is immersed within a Nafion.TM./methanol bath to impregnate the electrode with Nafion.TM.. A method for fabricating an anode for use in a organic fuel cell is described wherein metal alloys are deposited onto the electrode in an electro-deposition solution containing perfluorooctanesulfonic acid. A fuel additive containing perfluorooctanesulfonic acid for use with fuel cells employing a sulfuric acid electrolyte is also disclosed. New organic fuels, namely, trimethoxymethane, dimethoxymethane, and trioxane are also described for use with either conventional or improved fuel cells.

  18. Generator module architecture for a large solid oxide fuel cell power plant

    Science.gov (United States)

    Gillett, James E.; Zafred, Paolo R.; Riggle, Matthew W.; Litzinger, Kevin P.

    2013-06-11

    A solid oxide fuel cell module contains a plurality of integral bundle assemblies, the module containing a top portion with an inlet fuel plenum and a bottom portion receiving air inlet feed and containing a base support, the base supports dense, ceramic exhaust manifolds which are below and connect to air feed tubes located in a recuperator zone, the air feed tubes passing into the center of inverted, tubular, elongated, hollow electrically connected solid oxide fuel cells having an open end above a combustion zone into which the air feed tubes pass and a closed end near the inlet fuel plenum, where the fuel cells comprise a fuel cell stack bundle all surrounded within an outer module enclosure having top power leads to provide electrical output from the stack bundle, where the fuel cells operate in the fuel cell mode and where the base support and bottom ceramic air exhaust manifolds carry from 85% to all 100% of the weight of the stack, and each bundle assembly has its own control for vertical and horizontal thermal expansion control.

  19. High pressure operation of tubular solid oxide fuel cells and their intergration with gas turbines

    Energy Technology Data Exchange (ETDEWEB)

    Haynes, C.; Wepfer, W.J. [Georgia Institute of Technology, Atlanta, GA (United States)

    1996-12-31

    Fossil fuels continue to be used at a rate greater than that of their natural formation, and the current byproducts from their use are believed to have a detrimental effect on the environment (e.g. global warming). There is thus a significant impetus to have cleaner, more efficient fuel consumption alternatives. Recent progress has led to renewed vigor in the development of fuel cell technology, which has been shown to be capable of producing high efficiencies with relatively benign exhaust products. The tubular solid oxide fuel cell developed by Westinghouse Electric Corporation has shown significant promise. Modeling efforts have been and are underway to optimize and better understand this fuel cell technology. Thus far, the bulk of modeling efforts has been for operation at atmospheric pressure. There is now interest in developing high-efficiency integrated gas turbine/solid oxide fuel cell systems. Such operation of fuel cells would obviously occur at higher pressures. The fuel cells have been successfully modeled under high pressure operation and further investigated as integrated components of an open loop gas turbine cycle.

  20. Fabrication method for solid electrolyte fuel cell. Kotai denkaishitsu nenryo denchi no seizo hoho

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Y.; Kuru, N.; Uchida, S.

    1993-01-29

    In general, CaO stabilized ZrO2, NiO, Y2O3 stabilized ZrO2, and LaCoO3 are used for the substrate tube, fuel electrode, electrolyte and air electrode respectively in the solid oxide electrolyte fuel cell (SOFC). When SOFC generates power at approximately 1,000[degree]C, NiO of the fuel electrode is reduced to become Ni, tensile stress is produced at the fuel electrode at this time, and cracks produced in the fuel electrode propagate to the electrolyte and the air electrode, with a possibility of damaging the entire SOFC. According to this invention, a film of NiO which is the material for the fuel electrode is formed on the substrate tube which is then subjected to heat treatment to reduce NiO to Ni, and the electrolyte and the air electrode are laminated successively. By reduction heat treatment after the formation of the NiO fuel electrode, crack propagation from the fuel electrode to the electrolyte and the fuel electrode can be prevented even if hydrogen is flown during power generation because no NiO-Ni reaction occurs at the fuel electrode. 7 figs.

  1. Unified approach to the study of solid fuel combustion characteristics at high airflow speeds

    Science.gov (United States)

    Vnuchkov, D. A.; Lukashevich, S. V.; Nalivaychenko, D. G.; Zvegintsev, V. I.

    2017-10-01

    The main objective of the research is the development of guidelines for a unified approach to testing the combustion of different solid fuels in gaseous oxidant high-speed flow, so that research outcomes could be presented in a standardized and cohesive form. All the experiments were performed on a special experimental installation designed for quantification of the burning characteristics of different fuels in a wide range of the airflow parameters at the same geometry of the combustion chamber.

  2. Modelling of Physical, Chemical, and Material Properties of Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Jakub Kupecki

    2015-01-01

    Full Text Available This paper provides a review of modelling techniques applicable for system-level studies to account for physical, chemical, and material properties of solid oxide fuel cells. Functionality of 0D to 3D models is discussed and selected examples are given. Author provides information on typical length scales in evaluation of power systems with solid oxide fuel cells. In each section, proper examples of previous studies done in the field of 0D–3D modelling are recalled and discussed.

  3. Regenerable mixed copper-iron-inert support oxygen carriers for solid fuel chemical looping combustion process

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardane, Ranjani V.; Tian, Hanjing

    2016-12-20

    The disclosure provides an oxygen carrier for a chemical looping cycle, such as the chemical looping combustion of solid carbonaceous fuels, such as coal, coke, coal and biomass char, and the like. The oxygen carrier is comprised of at least 24 weight % (wt %) CuO, at least 10 wt % Fe2O3, and an inert support, and is typically a calcine. The oxygen carrier exhibits a CuO crystalline structure and an absence of iron oxide crystalline structures under XRD crystallography, and provides an improved and sustained combustion reactivity in the temperature range of 600.degree. C.-1000.degree. C. particularly for solid fuels such as carbon and coal.

  4. Polypropylene oil as fuel for solid oxide fuel cell with samarium doped-ceria (SDC)-carbonate as electrolyte

    Science.gov (United States)

    Syahputra, R. J. E.; Rahmawati, F.; Prameswari, A. P.; Saktian, R.

    2017-03-01

    The research focusses on converting polypropylene oil as pyrolysis product of polypropylene plastic into an electricity. The converter was a direct liquid fuel-solid oxide fuel cell (SOFC) with cerium oxide based material as electrolyte. The polypropylene vapor flowed into fuel cell, in the anode side and undergo oxidation reaction, meanwhile, the Oxygen in atmosphere reduced into oxygen ion at cathode. The fuel cell test was conducted at 400 - 600 °C. According to GC-MS analysis, the polypropylene oil consist of C8 to C27 hydrocarbon chain. The XRD analysis result shows that Na2CO3 did not change the crystal structure of SDC even increases the electrical conductivity. The maximum power density is 0.079 mW.cm-2 at 773 K. The open circuite voltage is 0.77 volt. Chemical stability test by analysing the single cell at before and after fuel cell test found that ionic migration occured during fuel cell operation. It is supported by the change of elemental composition in the point position of electrolyte and at the electrolyte-electrode interface

  5. Particulate matter chemical component concentrations and sources in settings of household solid fuel use.

    Science.gov (United States)

    Secrest, M H; Schauer, J J; Carter, E M; Baumgartner, J

    2017-11-01

    Particulate matter (PM) air pollution derives from combustion and non-combustion sources and consists of various chemical species that may differentially impact human health and climate. Previous reviews of PM chemical component concentrations and sources focus on high-income urban settings, which likely differ from the low- and middle-income settings where solid fuel (ie, coal, biomass) is commonly burned for cooking and heating. We aimed to summarize the concentrations of PM chemical components and their contributing sources in settings where solid fuel is burned. We searched the literature for studies that reported PM component concentrations from homes, personal exposures, and direct stove emissions under uncontrolled, real-world conditions. We calculated weighted mean daily concentrations for select PM components and compared sources of PM determined by source apportionment. Our search criteria yielded 48 studies conducted in 12 countries. Weighted mean daily cooking area concentrations of elemental carbon, organic carbon, and benzo(a)pyrene were 18.8 μg m-3 , 74.0 μg m-3 , and 155 ng m-3 , respectively. Solid fuel combustion explained 29%-48% of principal component/factor analysis variance and 41%-87% of PM mass determined by positive matrix factorization. Multiple indoor and outdoor sources impacted PM concentrations and composition in these settings, including solid fuel burning, mobile emissions, dust, and solid waste burning. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Solid Oxide Fuel Cell (SOFC) Development in Denmark

    DEFF Research Database (Denmark)

    Linderoth, Søren; Larsen, Peter Halvor; Mogensen, Mogens Bjerg

    2007-01-01

    is being up-scaled continuously. The durability of the standard stack design with standard cells has been tested for more than 13000 hours including nine full thermal cycles with an overall voltage degradation rate of about 1% per 1000 hours. Recently, the degradation rate has been significantly reduced...... by introduction of improved stack component materials. 75-cell stacks in the 1+ kW power range have been tested successfully. Stacks have been delivered in a pre-reduced state to partners and tested successfully in test systems with natural gas as fuel. The consortium of TOFC and RISØ has an extended program......The SOFC technology under development at Risø National Laboratory (RISØ) and Topsoe Fuel Cell A/S (TOFC) is based on an integrated approach ranging from basic materials research on single component level over development of cell and stack manufacturing technology to system studies and modelling...

  7. Artificial neural networks application for solid fuel slagging intensity predictions

    OpenAIRE

    Kakietek Sławomir; Szymczak Jerzy

    2017-01-01

    Slagging issues present in pulverized steam boilers very often lead to heat transfer problems, corrosion and not planned outages of boilers which increase the cost of energy production and decrease the efficiency of energy production. Slagging especially occurs in regions with reductive atmospheres which nowadays are very common due to very strict limitations in NOx emissions. Moreover alternative fuels like biomass which are also used in combustion systems from two decades in order to decrea...

  8. Effectiveness of paper-structured catalyst for the operation of biodiesel-fueled solid oxide fuel cell

    Science.gov (United States)

    Quang-Tuyen, Tran; Kaida, Taku; Sakamoto, Mio; Sasaki, Kazunari; Shiratori, Yusuke

    2015-06-01

    Mg/Al-hydrotalcite (HDT)-dispersed paper-structured catalyst (PSC) was prepared by a simple paper-making process. The PSC exhibited excellent catalytic activity for the steam reforming of model biodiesel fuel (BDF), pure oleic acid methyl ester (oleic-FAME, C19H36O2) which is a mono-unsaturated component of practical BDFs. The PSC exhibited fuel conversion comparable to a pelletized catalyst material, here, conventional Ni-zirconia cermet anode for solid oxide fuel cell (SOFC) with less than one-hundredth Ni weight. Performance of electrolyte-supported cell connected with the PSC was evaluated in the feed of oleic-FAME, and stable operation was achieved. After 60 h test, coking was not observed in both SOFC anode and PSC.

  9. Operating Point Optimization of a Hydrogen Fueled Hybrid Solid Oxide Fuel Cell-Steam Turbine (SOFC-ST Plant

    Directory of Open Access Journals (Sweden)

    Juanjo Ugartemendia

    2013-09-01

    Full Text Available This paper presents a hydrogen powered hybrid solid oxide fuel cell-steam turbine (SOFC-ST system and studies its optimal operating conditions. This type of installation can be very appropriate to complement the intermittent generation of renewable energies, such as wind generation. A dynamic model of an alternative hybrid SOFC-ST configuration that is especially suited to work with hydrogen is developed. The proposed system recuperates the waste heat of the high temperature fuel cell, to feed a bottoming cycle (BC based on a steam turbine (ST. In order to optimize the behavior and performance of the system, a two-level control structure is proposed. Two controllers have been implemented for the stack temperature and fuel utilization factor. An upper supervisor generates optimal set-points in order to reach a maximal hydrogen efficiency. The simulation results obtained show that the proposed system allows one to reach high efficiencies at rated power levels.

  10. A micro heater platform with fluid channels for testing micro-solid oxide fuel cell components

    OpenAIRE

    Jiang, Bo; Muralt, Paul; Heeb, Peter; Santis-Alvarez, Alejandro J.; Nabavi, Majid; Poulikakos, Dimos; Niedermann, Philippe; Maeder, Thomas

    2012-01-01

    Micro-scale solid oxide fuel cell is a promising power generation technology for portable devices such as laptop, medical devices and personal electronics. One of the key goals in design of μ-SOFC systems is to use common hydrocarbon fuels such as propane/butane, which requires an additional micro-scale gas-processing unit (GPU) to reform the fuel, avoiding the coking on the μ-SOFC membranes. However, no integrated micro-fabricated testing platform has been reported for evaluating the stabili...

  11. Thermodynamic analysis of synthetic hydrocarbon fuel production in pressurized solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Sun, Xiufu; Chen, Ming; Jensen, Søren Højgaard

    2012-01-01

    A promising way to store wind and solar electricity is by electrolysis of H2O and CO2 using solid oxide electrolysis cells (SOECs) to produce synthetic hydrocarbon fuels that can be used in existing fuel infrastructure. Pressurized operation decreases the cell internal resistance and enables...... hydrocarbon fuel and avoiding damage to the cells. The main parameters of cell operating temperature, pressure, inlet gas composition and reactant utilization are varied to examine how they influence cell thermoneutral and reversible potentials, in situ formation of methane and carbon at the Ni–YSZ electrode...

  12. Plant Characteristics of an Integrated Solid Oxide Fuel Cell Cycle and a Steam Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Plant characteristics of a system containing a solid oxide fuel cell (SOFC) cycle on the top of a Rankine cycle were investigated. Natural gas (NG) was used as the fuel for the plant. A desulfurization reactor removes the sulfur content in the fuel, while a pre-reformer broke down the heavier...... recovery steam generator (HRSG). The remaining energy of the off-gases was recycled back to the topping cycle for further utilization. Several parameter studies were carried out to investigate the sensitivity of the suggested plant. It was shown that the operation temperature of the desulfurization unit...

  13. A simulation study of Solid Oxide fuel cell for IGCC power generation using Aspen Plus

    DEFF Research Database (Denmark)

    Rudra, Souman; Kim, Hyung Taek

    2010-01-01

    operating conditions and using diverse fuels. The SOFC stack model developed using the chemical process flow sheet simulator Aspen Plus which is of equilibrium type and is based on Gibbs free energy minimization. The SOFC model performs heat and mass balances and considers the ohmic, activation......The solid oxide fuel cell (SOFC) is a promising technology for electricity generation. Sulfur free syngas from the gas cleaning unit serves as a fuel for SOFC in IGFC (Integrated gasification Fuel cell) power plant. It converts the chemical energy of the fuel gas directly to electric energy...... and therefore, very high efficiencies can be achieved. The high operating temperature of the SOFC also provides excellent possibilities for cogeneration application. The outputs from SOFC can be utilized by HRSG which helps to drive steam generator. Recent developments in modeling techniques has resulted...

  14. Thermodynamic Analysis of an Integrated Solid Oxide Fuel Cell Cycle with a Rankine Cycle

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2010-01-01

    Hybrid systems consisting of Solid Oxide Fuel Cells (SOFC) on the top of a Steam Turbine (ST) are investigated. The plants are fired by natural gas (NG). A desulfurization reactor removes the sulfur content in the fuel while a pre-reformer breaks down the heavier hydrocarbons. The pre-treated fuel...... enters then into the anode side of the SOFC. The remaining fuels after the SOFC stacks enter a burner for further burning. The off-gases are then used to produce steam for a Rankine cycle in a Heat Recovery Steam Generator (HRSG). Different system setups are suggested. Cyclic efficiencies up to 67......% are achieved which is considerably higher than the conventional Combined Cycles (CC). Both ASR (Adiabatic Steam Reformer) and CPO (Catalytic Partial Oxidation) fuel pre-reformer reactors are considered in this investigation....

  15. Numerical investigation of the heterogeneous combustion processes of solid fuels

    OpenAIRE

    Alganash, Blaid; Paul, M. C.; Watson, Ian.A.

    2015-01-01

    Two-phase computational modelling based on the Euler–Euler was developed to investigate the heterogeneous combustion processes of biomass, in the solid carbon phase, inside a newly designed combustion chamber (Model 1). A transient simulation was carried out for a small amount of carbon powder situated in a cup which was located at the centre of the combustion chamber. A heat source was provided to initiate the combustion with the air supplied by three injection nozzles. The results show that...

  16. Green conversion of municipal solid wastes into fuels and chemicals

    Directory of Open Access Journals (Sweden)

    Leonidas Matsakas

    2017-03-01

    Full Text Available Presently, the society is facing a serious challenge for the effective management of the increasing amount of produced municipal solid wastes. The accumulated waste has caused a series of environmental problems such as uncontrolled release of greenhouse gases. Moreover, the increasing amount of wastes has resulted in a shortage of areas available for waste disposal, resulting in a nonsustainable waste management. These problems led to serious public concerns, which in turn resulted in political actions aiming to reduce the amount of wastes reaching the environment. These actions aim to promote sustainable waste management solutions. The main objective of these policies is to promote the recycling of municipal solid waste and the conversion of waste to energy and valuable chemicals. These conversions can be performed using either biological (e.g., anaerobic digestion or thermochemical processes (e.g., pyrolysis. Research efforts during the last years have been fruitful, and many publications demonstrated the effective conversation of municipal solid waste to energy and chemicals. These processes are discussed in the current review article together with the change of the waste policy that was implemented in the EU during the last years.

  17. Solid oxide fuel cell systems development. Final report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    The main objective in this project has been to develop a generic and dynamic tool for SOFC systems simulation and development. Developing integrated fuel cell systems is very expensive and therefore having the right tools to reduce the development cost and time to market for products becomes an important feature. The tools developed in this project cover a wide range of needs in Dantherm Power, R and D, and can be divided into 3 categories: 1. Component selection modeling; to define component specification requirements and selection of suppliers. 2. Application simulation model built from scratch, which can simulate the interface between customer demand and system output and show operation behavior for different control settings. 3. System operation strategy optimization with respect to operation cost and customer benefits. a. Allows to see how system size, in terms of electricity and heat output, and operation strategy influences a specific business case. b. Gives a clear overview of how a different property, in the system, affects the economics (e.g. lifetime, electrical and thermal efficiency, fuel cost sensitivity, country of deployment etc.). The main idea behind the structure of the tool being separated into 3 layers is to be able to service different requirements, from changing stakeholders. One of the major findings in this project has been related to thermal integration between the existing installation in a private household and the fuel cell system. For a normal family requiring 4500 kWh of electricity a year, along with the possibility of only running the system during the heating season (winter), the heat storage demand is only 210kWh of heat with an approximate value of Dkr 160,- in extra gas consumption. In this case, it would be much more cost effective to dump the heat, in the house, and save the expense of adding heat storage to the system. This operation strategy is only valid in Denmark for the time being, since the feed-In-Tariff allows for a

  18. Biomass gasification integrated with a solid oxide fuel cell and Stirling engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    An integrated gasification solid oxide fuel cell (SOFC) and Stirling engine for combined heat and power application is analyzed. The target for electricity production is 120 kW. Woodchips are used as gasification feedstock to produce syngas, which is then used to feed the SOFC stacks...

  19. Thermodynamic Analysis of a Woodchips Gasification Integrated with Solid Oxide Fuel Cell and Stirling Engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2013-01-01

    Integrated gasification Solid Oxide Fuel Cell (SOFC) and Stirling engine for combined heat and power application is analysed. The target for electricity production is 120 kW. Woodchips are used as gasification feedstock to produce syngas which is utilized for feeding the SOFC stacks for electricity...

  20. Nickel/Yttria-stabilised zirconia cermet anodes for solid oxide fuel cells

    NARCIS (Netherlands)

    Primdahl, Søren

    1999-01-01

    This thesis deals with the porous Ni/yttria-stabilized zirconia (YSZ) cermet anode on a YSZ electrolyte for solid oxide fuel cells (SOFC). Such anodes are predominantly operated in moist hydrogen at 700°C to 1000°C, and the most important technological parameters are the polarization resistance and

  1. Analysis of anode functional layer for minimizing thermal stress in solid oxide fuel cell

    Science.gov (United States)

    Xie, Jiamiao; Hao, Wenqian; Wang, Fenghui

    2017-10-01

    Two-dimensional (2D) model is used to analyze the thermo-mechanical behavior of anode-supported solid oxide fuel cell for a given thermal loading. In order to reduce the thermal stress generated during the preparation and operation of solid oxide fuel cell, the optimized anode functional layer is introduced into solid oxide fuel cell. In this work, based on the hierarchical model theory, the anode functional layer is divided into several sub-layers. The thickness and NiO volume fraction of each sub-layer gradient change and are controlled by non-linear thickness gradient exponent and non-linear composition gradient exponent, respectively. The optimization schemes are obtained to minimize the anode axial stress, the electrolyte compressive stress and the layer interface stress significantly, and the change trend of the anode axial stress over the entire temperature range is also analyzed. The research in this paper provides theoretical basis for optimizing the anode-supported solid oxide fuel cell.

  2. Investigation into the Flow Properties of Coarse Solid Fuels for Use in Industrial Feed Systems

    Directory of Open Access Journals (Sweden)

    James M. Craven

    2015-01-01

    Full Text Available Material feeding and handling systems have been cited as one of the most common causes of process downtime where thermochemical conversion processes are concerned. New and emerging fuels come in a variety of forms, and if such fuels are to be deployed widely it is imperative that material feeding and handling systems are designed appropriately. This study proposes an approach for designing material feeding and handling systems for use with coarse solid fuels. The data obtained from this study indicates particle size to be one of the key issues affecting the flowability of bulk solids further to the uniformity in particle shape. Coarse bulk solid samples were shown to flow more freely than their milled and pulverised counterparts, generating higher degrees of flowability. The results from this study were also applied to a new feed system used for feeding solid fuels to high pressure processes named the Hydraulic Lock Hopper. In this study the Hydraulic Lock Hopper demonstrated the feeding of wood pellets, torrefied spruce pellets, and ground anthracite coal grains against a pressure of 25 barg in two modes of operation. Energy savings compared to conventional lock hopper systems were recorded in the region of 80%.

  3. Basic data biogas Germany. Solid fuels, biofuels, biogas; Basisdaten Bioenergie Deutschland. Festbrennstoffe, Biokraftstoffe, Biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-09-15

    The brochure ''Basic data biogas Germany'' gives statistical information about (a) renewable energies: primary energy consumption, power generation, energy supply, avoidance of greenhouse gases; (b) Solid fuels: energetic utilization, wood pellets, energy consumption, comparison to heating oil; (c) Biofuels: consumption, bioethanol, biodiesel, vegetable oils; (d) Biogas: biogas power plants, energy content, production, legal aspects.

  4. Development Of A Solid Oxide Fuel Cell Stack By Delphi And Battelle

    Energy Technology Data Exchange (ETDEWEB)

    Mukerjee, Subhasish; Shaffer, Steven J.; Zizelman, James; Chick, Lawrence A.; Baskaran, Suresh; Chou, Y. S.; Coyle, Christopher A.; Deibler, John E.; Maupin, Gary D.; Meinhardt, Kerry D.; Paxton, Dean M.; Peters, Timothy J.; Sprenkle, Vince L.; Weil, K. Scott; Williford, Rick E.

    2003-01-20

    Delphi and Battelle are developing a Solid Oxide Fuel Cell (SOFC) stack for transportation and residential applications. This paper describes the status of development of the Generation 2 stack and key progress made in addressing some of the challenges in this technology.

  5. Analysis of Gas Leakage and Current Loss of Solid Oxide Fuel Cells by Screen Printing

    DEFF Research Database (Denmark)

    Jia, Chuan; Han, Minfang; Chen, Ming

    2017-01-01

    Two types of anode supported solid oxide fuel cell (SOFC) NiO-YSZ/YSZ/GDC/LSCF with the same structure and different manufacturing process were tested. Gas leakage was suspected for cells manufactured with screen printing technique. Effective leak current densities for both types of cells were...

  6. Basic data biogas Germany. Solid fuels, biofuels, biogas; Basisdaten Bioenergie Deutschland. Festbrennstoffe - Biokraftstoffe - Biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-08-15

    The brochure ''Basic data biogas Germany'' gives statistical information about (a) renewable energies: primary energy consumption, power generation, energy supply, avoidance of greenhouse gases; (b) Solid fuels: energetic utilization, wood pellets, energy consumption, comparison to heating oil; (c) Biofuels: consumption, bioethanol, biodiesel, vegetable oils; (d) Biogas: biogas power plants, energy content, production, legal aspects.

  7. The study of flow and proton exchange interactions in the cylindrical solid oxide fuel cell

    CERN Document Server

    Saievar-Iranizad, E

    2002-01-01

    The solid oxide fuel cell operates at high temperature of about 1000 deg C. In this temperature, some known materials such as Ni, ... which is abundant in the nature, can be used as a catalyst in the electrodes. The electrolytes of such cell solid oxide fuel cell can be made through non-porous solid ceramics such as Zircon's (ZrO sub 2). It can be stabilized using a doped Yttrium oxide. The importance of Yttria-stabilised Zirconia at high temperature belongs to the transport of oxygen ions through the electrolyte. Oxygen using in the hot cathode side causes a considerable reduction in the concentration of oxygen molecules. The oxygen ions exchange through the electrolyte relates to the molecular oxygen concentration gradient between the anode and cathode. Applying fuels such as hydrogen or natural gas in the anode and its chemical reaction with oxygen ions transfer from cathode through the electrolyte, produce electricity, water and heat. To study the ion exchange and its interaction into solid oxide fuel cel...

  8. Operation strategy for solid oxide fuel cell systems for small-scale stationary applications

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2009-01-01

    Solid oxide fuel cell micro cogeneration systems have the potential to reduce domestic energy consumption by providing both heat and power on site without transmission losses. The high grade heat produced during the operation of the power causes high thermal transients during startup/shutdown pha...

  9. Solid Fuel in Kitchen and Acute Respiratory Tract Infection Among Under Five Children

    DEFF Research Database (Denmark)

    Acharya, Pawan; Mishra, Shiva Raj; Berg-Beckhoff, Gabriele

    2015-01-01

    This study assessed the association between use of solid fuel in kitchen and ARI among under five children in Nepal. The latest data from the Nepal Demographic and Health Survey 2011 were used. A total of 4,802 under 5 de-jure children were included in this analysis. Cough accompanied by short/ra...

  10. Recovery Act. Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration

    Energy Technology Data Exchange (ETDEWEB)

    Geiger, Gail E. [Delphi Automotive Systems, LLC., Gillingham (United Kingdom)

    2013-09-30

    Solid Oxide Fuel Cell Diesel Auxilliary Power Unit Demonstration Project. Summarizing development of Delphi’s next generation SOFC system as the core power plant to prove the viability of the market opportunity for a 3-5 kW diesel SOFC system. Report includes test and demonstration results from testing the diesel APU in a high visibility fleet customer vehicle application.

  11. Ab initio Defect Energetics in LaBO3 Perovskite Solid Oxide Fuel Cell Materials

    DEFF Research Database (Denmark)

    Lee, Yueh-Lin; Morgan, Dane; Kleis, Jesper

    2009-01-01

    Perovskite materials of the form ABO3 are a promising family of compounds for use in solid oxide fuel cell (SOFC) cathodes. Study of the physics of these compounds under SOFC conditions with ab initio methods is particularly challenging due to high temperatures, exchange of oxygen with O2 gas...

  12. Engineering bed models for solid fuel conversion process in grate-fired boilers

    DEFF Research Database (Denmark)

    Costa, M.; Massarotti, N.; Indrizzi, V.

    2014-01-01

    A comparison between two numerical models describing the thermo-chemical conversion process of a solid fuel bed in a grate-fired boiler is presented. Both models consider the incoming biomass as subjected to drying, pyrolysis, gasification and combustion. In the first approach the biomass bed is ...

  13. The liquid biodiesel extracted from pranajiwa (Sterculia Foetida) seeds as fuel for direct biofuel-solid oxide fuel cell

    Science.gov (United States)

    Rahmawati, Fitria; Syahputra, Rahmat J. E.; Yuniastuti, Endang; Prameswari, Arum P.; Nurcahyo, I. F.

    2017-03-01

    This research applied the liquid biodiesel extracted from Pranajiwa seeds (biodiesel-p) as fuel in Intermediate Temperature-Solid Oxide Fuel Cell, IT-SOFC, with an operational temperature of 400 - 600°C. FTIR analysis of the liquid biodiesel found that the liquid consist of some functional groups. By comparing the spectrum with the commercial biosolar as produced by Pertamina, Indonesia, it is found that there are differenet peaks at a wavenumber of 3472.98; 1872.00; and 724.30 cm-1. It indicates the presence of alcoholo molecules. Composite of Samarium doped-Ceria, SDC, with sodium carbonate, NaCO3, was used as the electrolyte, and it is named as NSDC. Meanwhile, the composite of NSDC with catalyst powder of LNC, producing NSDC-L was used as a cathode and as an anode. The liquid fuel vapourized at 150 °C before come into the fuel cell, and it was reformed inside the fuel cell tube which was set up at 400, 500, and 600 °C. The measurement found that the highest Open Circuite Voltage is 0.57 volt and the power density of 1.7 mW.cm-2 at 500 °C.

  14. Emission factors of carbonaceous particulate matter and polycyclic aromatic hydrocarbons from residential solid fuel combustions

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Guofeng [Jiangsu Academy of Environmental Science, Nanjing (China). Inst. of Atmospheric Sciences

    2014-07-01

    Emission inventory is basic for the understanding of environmental behaviors and potential effects of compounds, however, current inventories are often associated with relatively high uncertainties. One important reason is the lack of emission factors, especially for the residential solid fuel combustion in developing countries. In the present study, emission factors of a group of pollutants including particulate matter, organic carbon, elemental carbon (sometimes known as black carbon) and polycyclic aromatic hydrocarbons were measured for a variety of residential solid fuels including coal, crop straw, wood, and biomass pellets in rural China. The study provided a large number of emission factors that can be further used in emission estimation. Composition profiles and isomer ratios were investigated and compared so as to be used in source apportionment. In addition, the present study identified and quantified the influence of factors like fuel moisture, volatile matter on emission performance.

  15. Method for removing solid particulate material from within liquid fuel injector assemblies

    Science.gov (United States)

    Simandl, Ronald F.; Brown, John D.; Andriulli, John B.; Strain, Paul D.

    1998-01-01

    A method for removing residual solid particulate material from the interior of liquid fuel injectors and other fluid flow control mechanisms having or being operatively associated with a flow-regulating fixed or variable orifice. The method comprises the sequential and alternate introduction of columns of a non-compressible liquid phase and columns of a compressed gas phase into the body of a fuel injector whereby the expansion of each column of the gas phase across the orifice accelerates the liquid phase in each trailing column of the liquid phase and thereby generates turbulence in each liquid phase for lifting and entraining the solid particulates for the subsequent removal thereof from the body of the fuel injector.

  16. Electrolytic hydrogen fuel production with solid polymer electrolyte technology.

    Science.gov (United States)

    Titterington, W. A.; Fickett, A. P.

    1973-01-01

    A water electrolysis technology based on a solid polymer electrolyte (SPE) concept is presented for applicability to large-scale hydrogen production in a future energy system. High cell current density operation is selected for the application, and supporting cell test performance data are presented. Demonstrated cell life data are included to support the adaptability of the SPE system to large-size hydrogen generation utility plants as needed for bulk energy storage or transmission. The inherent system advantages of the acid SPE electrolysis technology are explained. System performance predictions are made through the year 2000, along with plant capital and operating cost projections.

  17. Solid Waste from Swine Wastewater as a Fuel Source for Heat Production

    Directory of Open Access Journals (Sweden)

    Myung-Ho Park

    2012-11-01

    Full Text Available This study was to evaluate the feasibility of recycling the solids separated from swine wastewater treatment process as a fuel source for heat production and to provide a data set on the gas emissions and combustion properties. Also, in this study, the heavy metals in ash content were analyzed for its possible use as a fertilizer. Proximate analysis of the solid recovered from the swine wastewater after flocculation with organic polymer showed high calorific (5,330.50 kcal/kg and low moisture (15.38% content, indicating that the solid separated from swine wastewater can be used as an alternative fuel source. CO and NOx emissions were found to increase with increasing temperature. Combustion efficiency of the solids was found to be stable (95 to 98% with varied temperatures. Thermogravimetry (TG and differential thermal analysis (DTA showed five thermal effects (four exothermic and one endothermic, and these effects were distinguished in three stages, water evaporation, heterogeneous combustion of hydrocarbons and decomposition reaction. Based on the calorific value and combustion stability results, solid separated from swine manure can be used as an alternative source of fuel, however further research is still warranted regarding regulation of CO and NOx emissions. Furthermore, the heavy metal content in ash was below the legal limits required for its usage as fertilizer.

  18. Final Technical Report, Oct 2004 - Nov. 2006, High Performance Flexible Reversible Solid Oxide Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Jie; Minh, Nguyen

    2007-02-21

    This report summarizes the work performed for the program entitled “High Performance Flexible Reversible Solid Oxide Fuel Cell” under Cooperative Agreement DE-FC36-04GO14351 for the U. S. Department of Energy. The overall objective of this project is to demonstrate a single modular stack that generates electricity from a variety of fuels (hydrogen and other fuels such as biomass, distributed natural gas, etc.) and when operated in the reverse mode, produces hydrogen from steam. This project has evaluated and selected baseline cell materials, developed a set of materials for oxygen and hydrogen electrodes, and optimized electrode microstructures for reversible solid oxide fuel cells (RSOFCs); and demonstrated the feasibility and operation of a RSOFC multi-cell stack. A 10-cell reversible SOFC stack was operated over 1000 hours alternating between fuel cell (with hydrogen and methane as fuel) and steam electrolysis modes. The stack ran very successfully with high power density of 480 mW/cm2 at 0.7V and 80% fuel utilization in fuel cell mode and >6 SLPM hydrogen production in steam electrolysis mode using about 1.1 kW electrical power. The hydrogen generation is equivalent to a specific capability of 2.59 Nm3/m2 with electrical energy demand of 3 kWh/Nm3. The performance stability in electrolysis mode was improved vastly during the program with a degradation rate reduction from 8000 to 200 mohm-cm2/1000 hrs. This was accomplished by increasing the activity and improving microstructure of the oxygen electrode. Both cost estimate and technology assessment were conducted. Besides the flexibility running under both fuel cell mode and electrolysis mode, the reversible SOFC system has the potentials for low cost and high efficient hydrogen production through steam electrolysis. The cost for hydrogen production at large scale was estimated at ~$2.7/kg H2, comparing favorably with other electrolysis techology.

  19. EFFECT SIGNIFICANCE ASSESSMENT OF THE THERMODYNAMICAL FACTORS ON THE SOLID OXIDE FUEL CELL OPERATION

    Directory of Open Access Journals (Sweden)

    V. A. Sednin

    2015-01-01

    Full Text Available Technologies of direct conversion of the fuel energy into electrical power are an upcoming trend in power economy. Over the last decades a number of countries have created industrial prototypes of power plants on fuel elements (cells, while fuel cells themselves became a commercial product on the world energy market. High electrical efficiency of the fuel cells allows predictting their further spread as part of hybrid installations jointly with gas and steam turbines which specifically enables achieving the electrical efficiency greater than 70 %. Nevertheless, investigations in the area of increasing efficiency and reliability of the fuel cells continue. Inter alia, research into the effects of oxidizing reaction thermodynamic parameters, fuel composition and oxidation reaction products on effectiveness of the solid oxide fuel cells (SOFC is of specific scientific interest. The article presents a concise analysis of the fuel type effects on the SOFC efficiency. Based on the open publications experimental data and the data of numerical model studies, the authors adduce results of the statistical analysis of the SOFC thermodynamic parameters effect on the effectiveness of its functioning as well as of the reciprocative factors of these parameters and gas composition at the inlet and at the outlet of the cell. The presented diagrams reflect dimension of the indicated parameters on the SOFC operation effectiveness. The significance levels of the above listed factors are ascertained. Statistical analysis of the effects of the SOFC functionning process thermodynamical, consumption and concentration parameters demonstrates quintessential influence of the reciprocative factors (temperature – flow-rate and pressure – flow-rate and the nitrogen N2 and oxygen O2 concentrations on the operation efficiency in the researched range of its functioning. These are the parameters to be considered on a first-priority basis while developing mathematical models

  20. A Theoretical Solid Oxide Fuel Cell Model for Systems Controls and Stability Design

    Science.gov (United States)

    Kopasakis, George; Brinson, Thomas; Credle, Sydni

    2008-01-01

    As the aviation industry moves toward higher efficiency electrical power generation, all electric aircraft, or zero emissions and more quiet aircraft, fuel cells are sought as the technology that can deliver on these high expectations. The hybrid solid oxide fuel cell system combines the fuel cell with a micro-turbine to obtain up to 70% cycle efficiency, and then distributes the electrical power to the loads via a power distribution system. The challenge is to understand the dynamics of this complex multidiscipline system and the design distributed controls that take the system through its operating conditions in a stable and safe manner while maintaining the system performance. This particular system is a power generation and a distribution system, and the fuel cell and micro-turbine model fidelity should be compatible with the dynamics of the power distribution system in order to allow proper stability and distributed controls design. The novelty in this paper is that, first, the case is made why a high fidelity fuel cell mode is needed for systems control and stability designs. Second, a novel modeling approach is proposed for the fuel cell that will allow the fuel cell and the power system to be integrated and designed for stability, distributed controls, and other interface specifications. This investigation shows that for the fuel cell, the voltage characteristic should be modeled but in addition, conservation equation dynamics, ion diffusion, charge transfer kinetics, and the electron flow inherent impedance should also be included.

  1. Characterization and Detailed Analysis of Regression Behavior for HTPB Solid Fuels Containing High Aluminum Loadings

    Science.gov (United States)

    Kibbey, Timothy P.; Cortopassi, Andrew C.; Boyer, Eric C.

    2017-01-01

    NASA Marshall Space Flight Center's Materials and Processes Department, with support from the Propulsion Systems Department, has renewed the development and maintenance of a hybrid test bed for exposing ablative thermal protection materials to an environment similar to that seen in solid rocket motors (SRM). The Solid Fuel Torch (SFT), operated during the Space Shuttle program, utilized gaseous oxygen for oxidizer and an aluminized hydroxyl-terminated polybutadiene (HTPB) fuel grain to expose a converging section of phenolic material to a 400 psi, 2-phase flow combustion environment. The configuration allows for up to a 2 foot long, 5 inch diameter fuel grain cartridge. Wanting to now test rubber insulation materials with a turn-back feature to mimic the geometry of an aft dome being impinged by alumina particles, the throat area has now been increased by several times to afford flow similarity. Combined with the desire to maintain a higher operating pressure, the oxidizer flow rate is being increased by a factor of 10. Out of these changes has arisen the need to characterize the fuel/oxidizer combination in a higher mass flux condition than has been previously tested at MSFC, and at which the literature has little to no reporting as well. For (especially) metalized fuels, hybrid references have pointed out possible dependence of fuel regression rate on a number of variables: mass flux, G - oxidizer only (G0), or - total mass flux (Gtot), Length, L, Pressure, P, and Diameter, D.

  2. Indoor Air Pollution and Health in Ghana: Self-Reported Exposure to Unprocessed Solid Fuel Smoke.

    Science.gov (United States)

    Armah, Frederick A; Odoi, Justice O; Luginaah, Isaac

    2015-06-01

    Most countries in Sub-Saharan Africa including Ghana still depend extensively on unprocessed solid cooking fuels with many people exposed on a daily basis to harmful emissions and other health risks. In this study, using complementary log-log multivariate models, we estimated the health effects of exposure to smoke from unprocessed wood in four regions of Ghana while controlling for socio-environmental and socio-demographic factors. The results show that the distribution of self-reported exposure to smoke was highest among participants in the Northern region, rural dwellers, the 25-49 age groups, individuals with no education, and married women. As expected, exposure to smoke was higher in crowded households and in communities without basic social amenities. Region, residential locality, housing quality (type of roofing, floor and exterior materials), self-reported housing condition, and access to toilet facilities were associated with self-reported exposure to solid fuel smoke. Participants living in urban areas were less likely (OR = 0.82, ρ ≤ 0.01) to be exposed to solid fuel smoke compared to their rural counterparts. An inverse relationship between self-reported housing condition and exposure to solid fuel smoke was observed and persisted even after adjustments were made for confounding variables in the demographic model. In Ghana, the cost and intermittent shortages of liquefied petroleum gas and other alternative fuel sources hold implications for the willingness of the poor to shift to their use. Thus, the poorest rural populations with nearly no cash income and electricity, but with access to wood and/or agricultural waste, are unlikely to move to clean fuels or use significantly improved stoves without large subsidies, which are usually not sustainable. However, there appears to be large populations between these extremes that can be targeted by efforts to introduce improved stoves.

  3. Independent and combined effects of maternal smoking and solid fuel on infant and child mortality in sub-Saharan Africa.

    Science.gov (United States)

    Akinyemi, Joshua O; Adedini, Sunday A; Wandera, Stephen O; Odimegwu, Clifford O

    2016-12-01

    To estimate the independent and combined risks of infant and child mortality associated with maternal smoking and use of solid fuel in sub-Saharan Africa. Pooled weighted data on 143 602 under-five children in the most recent demographic and health surveys for 15 sub-Saharan African countries were analysed. The synthetic cohort life table technique and Cox proportional hazard models were employed to investigate the effect of maternal smoking and solid cooking fuel on infant (age 0-11 months) and child (age 12-59 months) mortality. Socio-economic and other confounding variables were included as controls. The distribution of the main explanatory variable in households was as follows: smoking + solid fuel - 4.6%; smoking + non-solid fuel - 0.22%; no smoking + solid fuel - 86.9%; and no smoking + non-solid fuel - 8.2%. The highest infant mortality rate was recorded among children exposed to maternal smoking + solid fuel (72 per 1000 live births); the child mortality rate was estimated to be 54 per 1000 for this group. In full multivariate models, the risk of infant death was 71% higher among those exposed to maternal smoking + solid fuel (HR = 1.71, CI: 1.29-2.28). For ages 12 to 59 months, the risk of death was 99% higher (HR = 1.99, CI: 1.28-3.08). Combined exposures to cigarette smoke and solid fuel increase the risks of infant and child mortality. Mothers of under-five children need to be educated about the danger of smoking while innovative approaches are needed to reduce the mortality risks associated with solid cooking fuel. © 2016 John Wiley & Sons Ltd.

  4. Effect of Composting Parameters on the Power Performance of Solid Microbial Fuel Cells

    Directory of Open Access Journals (Sweden)

    Chin-Tsan Wang

    2015-09-01

    Full Text Available Nowadays, solid organic waste is of major environmental concern and is reaching critical levels worldwide. Currently, a form of natural decomposition, known as composting technology, is widely used to deal with organic waste. This method is applied to enhance the performance of solid microbial fuel cells (SMFCs in this study. Operational composting parameters (carbon/nitrogen ratio, moisture content and pH value are investigated to explore the optimal power performance of solid microbial fuel cells (SMFCs. Results indicate that the carbon/nitrogen ratio and the moisture content displayed the most significant impact on SMFCs. When the carbon/nitrogen ratio is 31.4 and moisture content is 60%, along with a pH value of 6–8, a better SMFC power performance would be obtained. These findings would provide positive information regarding the application of compost in SMFCs.

  5. Diffusion and conversion impedance in solid oxide fuel cells

    DEFF Research Database (Denmark)

    Jacobsen, Torben; Hendriksen, Peter Vang; Koch, Søren

    2008-01-01

    In fuel cell electrodes where the thin, active electrode layer is supported by a porous layer the diffusion processes as well as the change in the gas phase composition due to the conversion of reactants will influence the cell impedance. Two models are developed for the description...... to consumption of reactants and accumulation of products. For simplicity this model is restricted to cases dominated by mass transfer and conversion of the gas supply. Qualitatively the predictions by both models are alike. At high frequencies a Warburg diffusion impedance is seen. Depending on the dimensions...... of the gas volume relative to the supporting layer this may turn towards the real axis as a nernstian diffusion impedance, or directly into the semicircle dominating the low frequency region....

  6. Development of low temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Bakker, W.T.; Goldstein, R. [Electric Power Research Institute, Palo Alto, CA (United States)

    1996-12-31

    The historical focus of the electric utility industry has been central station power plants. These plants are usually sited outside urban areas and electricity was delivered via high voltage transmission lines. Several things are beginning to change this historical precedent One is the popular concern with EMF as a health hazard. This has rendered the construction of new lines as well as upgrading old ones very difficult. Installation of power generating equipment near the customer enables the utility to better utilize existing transmission and distribution networks and defer investments. Power quality and lark of disturbances and interruptions is also becoming increasingly more important to many customers. Grid connected, but dedicated small power plants can greatly improve power quality. Finally the development of high efficiency, low emission, modular fuel cells promises near pollution free localized power generation with an efficiency equal to or exceeding that of even the most efficient central power stations.

  7. Why solid oxide cells can be reversibly operated in solid oxide electrolysis cell and fuel cell modes?

    Science.gov (United States)

    Chen, Kongfa; Liu, Shu-Sheng; Ai, Na; Koyama, Michihisa; Jiang, San Ping

    2015-12-14

    High temperature solid oxide cells (SOCs) are attractive for storage and regeneration of renewable energy by operating reversibly in solid oxide electrolysis cell (SOEC) and solid oxide fuel cell (SOFC) modes. However, the stability of SOCs, particularly the deterioration of the performance of oxygen electrodes in the SOEC operation mode, is the most critical issue in the development of high performance and durable SOCs. In this study, we investigate in detail the electrochemical activity and stability of La0.8Sr0.2MnO3 (LSM) oxygen electrodes in cyclic SOEC and SOFC modes. The results show that the deterioration of LSM oxygen electrodes caused by anodic polarization can be partially or completely recovered by subsequent cathodic polarization. Using in situ assembled LSM electrodes without pre-sintering, we demonstrate that the deteriorated LSM/YSZ interface can be repaired and regenerated by operating the cells under cathodic polarization conditions. This study for the first time establishes the foundation for the development of truly reversible and stable SOCs for hydrogen fuel production and electricity generation in cyclic SOEC and SOFC operation modes.

  8. The effect of stirring in the hydrothermal process to convert the mixed municipal solid waste into uniform solid fuel

    Science.gov (United States)

    Prawisudha, P.; Mu'min, G. F.; Yoshikawa, K.; Pasek, A. D.

    2016-06-01

    An innovative waste treatment technology has been developed in Indonesia to treat the mixed municipal solid waste into a solid fuel by employing the hydrothermal process. A mixture of organic and plastic waste was treated in a 2.5 L reactor using saturated steam in the temperature range of 120 to 180 °C. Two modes of operation were employed to achieve two different goals, i.e. without stirring (NS mode) and with stirring (WS mode). It was observed that both modes resulted in increasing density of product up to twofold of the raw MSW. In NS mode, the processed mixed MSW was converted into two different products; however, in WS mode the bulky plastic was converted into small granules, producing a uniform product. The results suggest that by hydrothermal treatment, the organic fibers in the organic parts are trapped into the plastic, and the stirring breaks the bulky plastics, producing uniform granules suitable as solid fuel. Therefore, the stirring during the hydrothermal process can be a solution to treat the MSW as it is, without any separation, to produce a clean and renewable energy source.

  9. Strategies for Carbon and Sulfur Tolerant Solid Oxide Fuel Cell Materials, Incorporating Lessons from Heterogeneous Catalysis.

    Science.gov (United States)

    Boldrin, Paul; Ruiz-Trejo, Enrique; Mermelstein, Joshua; Bermúdez Menéndez, José Miguel; Ramı Rez Reina, Tomás; Brandon, Nigel P

    2016-11-23

    Solid oxide fuel cells (SOFCs) are a rapidly emerging energy technology for a low carbon world, providing high efficiency, potential to use carbonaceous fuels, and compatibility with carbon capture and storage. However, current state-of-the-art materials have low tolerance to sulfur, a common contaminant of many fuels, and are vulnerable to deactivation due to carbon deposition when using carbon-containing compounds. In this review, we first study the theoretical basis behind carbon and sulfur poisoning, before examining the strategies toward carbon and sulfur tolerance used so far in the SOFC literature. We then study the more extensive relevant heterogeneous catalysis literature for strategies and materials which could be incorporated into carbon and sulfur tolerant fuel cells.

  10. Computational Fluid Dynamics calculation of a planar solid oxide fuel cell design running on syngas

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2017-12-01

    Full Text Available The present study deals with modelling and validation of a planar Solid Oxide Fuel Cell (SOFC design fuelled by gas mixture of partially pre-reformed methane. A 3D model was developed using the ANSYS Fluent Computational Fluid Dynamics (CFD tool that was supported by an additional Fuel Cell Tools module. The governing equations for momentum, heat, gas species, ion and electron transport were implemented and coupled to kinetics describing the electrochemical and reforming reactions. In the model, the Water Gas Shift reaction in a porous anode layer was included. Electrochemical oxidation of hydrogen and carbon monoxide fuels were both considered. The developed model enabled to predict the distributions of temperature, current density and gas flow in the fuel cell.

  11. Hydrogen Fueled Hybrid Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) System for Long-Haul Rail Application

    Science.gov (United States)

    Chow, Justin Jeff

    Freight movement of goods is the artery for America's economic health. Long-haul rail is the premier mode of transport on a ton-mile basis. Concerns regarding greenhouse gas and criteria pollutant emissions, however, have motivated the creation of annually increasing locomotive emissions standards. Health issues from diesel particulate matter, especially near rail yards, have also been on the rise. These factors and the potential to raise conventional diesel-electric locomotive performance warrants the investigation of using future fuels in a more efficient system for locomotive application. This research evaluates the dynamic performance of a Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT) Hybrid system operating on hydrogen fuel to power a locomotive over a rail path starting from the Port of Los Angeles and ending in the City of Barstow. Physical constraints, representative locomotive operation logic, and basic design are used from a previous feasibility study and simulations are performed in the MATLAB Simulink environment. In-house controls are adapted to and expanded upon. Results indicate high fuel-to-electricity efficiencies of at least 54% compared to a conventional diesel-electric locomotive efficiency of 35%. Incorporation of properly calibrated feedback and feed-forward controls enables substantial load following of difficult transients that result from train kinematics while maintaining turbomachinery operating requirements and suppressing thermal stresses in the fuel cell stack. The power split between the SOFC and gas turbine is deduced to be a deterministic factor in the balance between capital and operational costs. Using hydrogen results in no emissions if renewable and offers a potential of 24.2% fuel energy savings for the rail industry.

  12. Iron-based perovskite cathodes for solid oxide fuel cells

    Science.gov (United States)

    Ralph, James M.; Rossignol, Cecile C.R.; Vaughey, John T.

    2007-01-02

    An A and/or A' site deficient perovskite of general formula of (A.sub.1-xA'.sub.x).sub.1-yFeO.sub.3-.delta. or of general formula A.sub.1-x-yA'.sub.xFeO.sub.3-67, wherein A is La alone or with one or more of the rare earth metals or a rare earth metal other than Ce alone or a combination of rare earth metals and X is in the range of from 0 to about 1; A' is Sr or Ca or mixtures thereof and Y is in the range of from about 0.01 to about 0.3; .delta. represents the amount of compensating oxygen loss. If either A or A' is zero the remaining A or A' is deficient. A fuel cell incorporating the inventive perovskite as a cathode is disclosed as well as an oxygen separation membrane. The inventive perovskite is preferably single phase.

  13. Chemical durability of Solid Oxide Fuel Cells: Influence of impurities on long-term performance

    Science.gov (United States)

    Sasaki, Kazunari; Haga, Kengo; Yoshizumi, Tomoo; Minematsu, Daisuke; Yuki, Eiji; Liu, RunRu; Uryu, Chie; Oshima, Toshihiro; Ogura, Teppei; Shiratori, Yusuke; Ito, Kohei; Koyama, Michihisa; Yokomoto, Katsumi

    Because of the fuel flexibility of Solid Oxide Fuel Cells (SOFCs), various types of fuels may be applied directly or via a simple reforming process, including hydrocarbons, alcohols, coal gas, biogas, besides hydrogen. However, various types of minor constituents in practical fuels and/or from the system components can cause chemical degradation of SOFCs, such as anode and cathode poisoning phenomena. In this study, we compare the influence of various external impurities, including sulfur, chlorine, phosphorus, boron, and siloxane for anodes, and H 2O and SO 2 for cathodes, on SOFC performance to have a general overview on long-term chemical durability of SOFCs. Chemical compatibility of Ni with foreign species has also been thermochemically considered. Using common model cells, the stability of cell voltage, electrode overpotential, and ohmic loss up to 3000 h has been experimentally examined for H 2-based fuels, for hydrocarbon-based fuels, and for partially pre-reformed CH 4-based fuels. Increase in degradation rate by impurities was verified for various operational parameters. Impurity poisoning mechanisms are discussed for each specific impurity.

  14. Reversible solid oxide cells for bidirectional energy conversion in spot electricity and fuel markets

    Science.gov (United States)

    Villarreal Singer, Diego

    The decarbonization of the energy system is one of the most complex and consequential challenges of the 21st century. Meeting this challenge will require the deployment of existing low carbon technologies at unprecedented scales and rates and will necessitate the development of new technologies that have the ability to transform variable renewable energy into high energy density products. Reversible Solid Oxide Cells (RSOCs) are electrochemical devices that can function both as fuel cells or electrolyzers: in fuel cell mode, RSOCs consume a chemical fuel (H2, CO, CH4, etc.) to produce electrical power, while in electrolysis mode they consume electric power and chemical inputs (H2O, CO2) to produce a chemical fuel (H2, CO, CH4, etc.). As such, RSOC systems can be thought of as flexible "energy hubs" that have unique potential to bridge the low power density renewable infrastructure with that of high energy density fuels in an efficient, dynamic, and bidirectional fashion. This dissertation explores the different operational sensitivities and design trade-offs of a methane based RSOC system, investigates the optimum operating strategies for a system that adapts to variations in the hourly spot electricity and fuel prices in Western Denmark, and provides an economic analysis of the system under a wide variety of design assumptions, operational strategies, and fuel and electricity market structures. (Abstract shortened by ProQuest.).

  15. Solid Oxide Fuel Cell/Gas Turbine Hybrid Cycle Technology for Auxiliary Aerospace Power

    Science.gov (United States)

    Steffen, Christopher J., Jr.; Freeh, Joshua E.; Larosiliere, Louis M.

    2005-01-01

    A notional 440 kW auxiliary power unit has been developed for 300 passenger commercial transport aircraft in 2015AD. A hybrid engine using solid-oxide fuel cell stacks and a gas turbine bottoming cycle has been considered. Steady-state performance analysis during cruise operation has been presented. Trades between performance efficiency and system mass were conducted with system specific energy as the discriminator. Fuel cell performance was examined with an area specific resistance. The ratio of fuel cell versus turbine power was explored through variable fuel utilization. Area specific resistance, fuel utilization, and mission length had interacting effects upon system specific energy. During cruise operation, the simple cycle fuel cell/gas turbine hybrid was not able to outperform current turbine-driven generators for system specific energy, despite a significant improvement in system efficiency. This was due in part to the increased mass of the hybrid engine, and the increased water flow required for on-board fuel reformation. Two planar, anode-supported cell design concepts were considered. Designs that seek to minimize the metallic interconnect layer mass were seen to have a large effect upon the system mass estimates.

  16. Mutagenicity of particle emissions from solid fuel cookstoves: A literature review and research perspective.

    Science.gov (United States)

    Shen, Guofeng

    2017-07-01

    Household solid fuel use is a major source of many air pollutants causing severe air pollution and adverse health outcomes. In evaluation of health impacts of household air pollution, it is essential to characterize toxic properties like mutagenicity of residential fuel combustion emissions and exposure assessments. Mutagenicity of emissions from solid fuel cookstoves were analyzed through a literature review. T98 and TA100 strains are two most widely used strains in mutagenic Ames test, and results for these two strains are generally positively correlated though they have different endpoints. Direct and indirect mutagenic activities are positively correlated, and statistically insignificantly different though indirect mutagenic emissions are apparently higher. Mutagenicity emission factors on the basis of fuel energy (MJ) or useful energy delivered (MJd) for solid fuel cookstoves vary in nearly 3 orders of magnitude, ranging from 3.0×10 4 rev./MJd to 1.8×10 7 rev./MJd (or 1.1×10 4 rev./MJ to 4.2×10 6 rev./MJ). Low mutagenic emissions are reported for high efficiency stoves such as a forced-draft one. Mutagenicity emission factors are positively correlated with emissions of PM 2.5 . Relationship between mutagenicity and polycyclic aromatic hydrocarbons (PAHs) emissions is inconsistent among studies as PAHs are minor fractions of toxic organics contributing to the total mutagenicity. Generally, studies on mutagenicity of emissions from household cookstoves are very limited, and future studies are encouraged on mutagenic emissions from different fuel types and household stoves, evaluation of mutagenic activities of both gaseous and particulate emissions, and toxicology and exposure assessments of household air pollution. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Three dimensional CFD modeling and experimental validation of a single chamber solid oxide fuel cell fed by methane

    Science.gov (United States)

    Nguyen, H. T.; Le, M. V.; Nguyen, T. A.; Nguyen, T. A. N.

    2017-06-01

    The solid oxide fuel cell is one of the promising technologies for future energy demand. Solid oxide fuel cell operated in the single-chamber mode exhibits several advantages over conventional single oxide fuel cell due to the simplified, compact, sealing-free cell structure. There are some studies on simulating the behavior of this type of fuel cell but they mainly focus on the 2D model. In the present study, a three-dimensional numerical model of a single chamber solid oxide fuel cell (SOFC) is reported and solved using COMSOL Multiphysics software. Experiments of a planar button solid oxide fuel cell were used to verify the simulation results. The system is fed by methane and oxygen and operated at 700°C. The cathode is LSCF6482, the anode is GDC-Ni, the electrolyte is LDM and the operating pressure is 1 atm. There was a good agreement between the cell temperature and current voltage estimated from the model and measured from the experiment. The results indicate that the model is applicable for the single chamber solid oxide fuel cell and it can provide a basic for the design, scale up of single chamber solid oxide fuel cell system.

  18. Simulation of tubular solid oxide fuel cell behavior for integration into gas turbine cycles

    Science.gov (United States)

    Haynes, Comas Lamar

    Models have been developed and validated for the characterization of tubular solid oxide fuel cells (TSOFCs) and a corresponding fuel cell/gas turbine (FC/GT) power cycle. This promising area of technology is expected to attain near-term commercialization (most notably the SiemensWestinghouse "SureCell" initiative). There is a need for continued conceptual design research in order for the full potential of these systems to be realized. Parametric studies were performed to delineate the impact of cell stack operating conditions on power generation, cell stack thermal management, independent cell load-following and performance quality. The diverse operating conditions included variations in physical cell design, stack pressure, operating voltage, stoichiometric number and stack fuel utilization. A number of novel findings are reported throughout the thesis. As an example, it has been shown that lowering cell stack fuel utilization has a number of benefits for both the simple TSOFC arrangement and the hybrid TSOFC/ GT scenario. The cell stack produces more power at lower fuel utilizations, because fuel supply to the stack actually increases. Additionally, fuel depletion issues (i.e., Nernst potential decrease and smaller limiting currents) are not as influential. A gas turbine bottoming engine would also increase in power production, at lower stack fuel utilizations, because a greater amount of fuel would then fire it. Note that power generation expense is measured per unit rating (e.g., $/kW). Increasing power capacity may then be a means of lowering cost, which is the key obstacle to commercialization. Another cost reduction may stein from the greater contribution of turbomachinery to system power generation, when stack fuel utilization is lowered. FC/GT system efficiency remains stable across a wide domain of cell stack fuel utilizations. This is a result of both the indirect internally reforming (IIR) fuel processor efficiency and Brayton cycle regeneration

  19. Thermodynamic Investigation of an Integrated Gasification Plant with Solid Oxide Fuel Cell and Steam Cycles

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2012-01-01

    A gasification plant is integrated on the top of a solid oxide fuel cell (SOFC) cycle, while a steam turbine (ST) cycle is used as a bottoming cycle for the SOFC plant. The gasification plant was fueled by woodchips to produce biogas and the SOFC stacks were fired with biogas. The produced gas...... integration configurations are completely novel and have not been studied elsewhere. Plant efficiencies of 56% were achieved under normal operation which was considerably higher than the IGCC (Integrated Gasification Combined Cycle) in which a gasification plant is integrated with a gas turbine and a steam...

  20. High temperature solid oxide regenerative fuel cell for solar photovoltaic energy storage

    Science.gov (United States)

    Bents, David J.

    1987-01-01

    A hydrogen-oxygen regenerative fuel cell energy storage system based on high temperature solid oxide fuel cell technology is discussed which has application to darkside energy storage for solar photovoltaics. The forward and reverse operating cycles are described, and heat flow, mass, and energy balance data are presented to characterize the system's performance and the variation of performance with changing reactant storage pressure. The present system weighs less than nickel hydrogen battery systems after 0.7 darkside operation, and it maintains a specific weight advantage over radioisotope generators for discharge periods up to 72 hours.

  1. Hydrogen and synthetic fuel production using pressurized solid oxide electrolysis cells

    DEFF Research Database (Denmark)

    Jensen, Søren Højgaard; Sun, Xiufu; Ebbesen, Sune

    2010-01-01

    Wind and solar power is troubled by large fluctuations in delivery due to changing weather. The surplus electricity can be used in a Solid Oxide Electrolyzer Cell (SOEC) to split CO2 + H2O into CO + H2 (+O2). The synthesis gas (CO + H2) can subsequently be catalyzed into various types of synthetic...... fuels using a suitable catalyst. As the catalyst operates at elevated pressure the fuel production system can be simplified by operating the SOEC at elevated pressure. Here we present the results of a cell test with pressures ranging from 0.4 bar to 10 bar. The cell was tested both as an SOEC...

  2. Spectroelectrochemical cell for in situ studies of solid oxide fuel cells

    DEFF Research Database (Denmark)

    Hagen, Anke; Traulsen, Marie Lund; Kiebach, Wolff-Ragnar

    2012-01-01

    Solid oxide fuel cells (SOFCs) are able to produce electricity and heat from hydrogen- or carbon-containing fuels with high efficiencies and are considered important cornerstones for future sustainable energy systems. Performance, activation and degradation processes are crucial parameters to con...... and in the presence of relevant gases. Simultaneous spectroscopic and electrochemical evaluation by using X-ray absorption spectroscopy and electrochemical impedance spectroscopy is possible....... on materials and structural properties, preferably at the atomic level. A characterization of these properties under operation is desired. As SOFCs operate at temperatures around 1073 K, this is a challenge. A spectroelectrochemical cell was designed that is able to study SOFCs at operating temperatures...

  3. Bond layer for a solid oxide fuel cell, and related processes and devices

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jian; Striker, Todd-Michael; Renou, Stephane; Gaunt, Simon William

    2017-03-21

    An electrically-conductive layer of material having a composition comprising lanthanum and strontium is described. The material is characterized by a microstructure having bimodal porosity. Another concept in this disclosure relates to a solid oxide fuel cell attached to at least one cathode interconnect by a cathode bond layer. The bond layer includes a microstructure having bimodal porosity. A fuel cell stack which incorporates at least one of the cathode bond layers is also described herein, along with related processes for forming the cathode bond layer.

  4. Micro solid oxide fuel cell on the chip. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Stutz, M.; Hotz, N.; Bieri, N.; Poulikakos, D.

    2006-07-01

    The aim of this project is the numerical and experimental investigation of hydrocarbon-to-syngas reforming in micro reformers for incorporation into an entire micro fuel cell system. Numerical simulations are used to achieve deeper understanding of several determining aspects in such a micro reformer. These insights are used to optimize the reforming performance by proper choice of operational and geometrical parameters of a reformer. These numerical results are continued by comprehensive experimental studies. In the first chapter, the effect of wall conduction of a tubular methane micro reformer is investigated numerically. Methane is used as the representative hydrocarbon because its detailed surface reaction mechanism is known. It is found that the axial wall conduction can strongly influence the performance of the microreactor and should not be neglected without a careful a priori investigation of its impact. In the second chapter, the effect of the catalyst amount and reactor geometry on the reforming process was investigated. It was found that the hydrogen selectivity changes significantly with varying catalyst loading. Thus, the reaction path leading to higher hydrogen production becomes more important by increasing the catalyst surface site density on the active surface. Another unexpected result is the presence of optimum channel geometry and optimum catalyst amount. In the third chapter of this project, the capability of flame-made Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} nanoparticles catalyzing the reforming of butane to H{sub 2}- and CO-rich syngas was investigated experimentally in a packed bed reactor. The main goal of this study was the efficient reforming of butane at temperatures between 500 and 600 {sup o}C for a micro intermediate-temperature SOFC system. Our results showed that Rh/Ce{sub 0.5}Zr{sub 0.5}O{sub 2} nanoparticles proved to be a very promising material for butane-to-syngas reforming with complete butane conversion and a hydrogen yield of 77

  5. Solid oxide fuels cells - Assessment of the technology from an industrial perspective

    Energy Technology Data Exchange (ETDEWEB)

    Paelsson, Jens; Boegild Hansen, John, Christiansen, Niel; Nielsen, Jens Ulrik; Kristensen, Steen [Haldor Topsoee A/S, Lyngby (Denmark)

    2003-09-01

    Fuel cells can play a large role in future energy supply as being a clean and efficient power and heat generator. One promising fuel cell type, SOFC, utilises mainly ceramic materials and operates at elevated temperatures. The inherent advantages of high temperature fuel cells, such as internal reforming of methane and waste heat production at high temperatures, lower the demands on the fuel processing system and lead to higher efficiency compared with low temperature fuel cells. Haldor Topsoee A/S has been active in the fuel cell area for a long time primarily in the fuel cell processing field. Today, the company has an extended development programme to bring to market SOFC technology. The cell design used is the planar SOFC from Risoe National Laboratory, which is of the anode-supported type. This paper deals with a thermodynamic analysis of an atmospheric SOFC based CHP system. Using natural gas as feed, an electric efficiency of more than 55% (88% total) was predicted. In a comparison made with a PEMFC or solid polymer fuel cell system, the SOFC system comes out superior. An energy analysis showed relatively small losses of the SOFC system compared with those of the PEMFC system. In a separate study on flow design for the stack it was found that the preferred flow geometry is counter-current flow, as a more homogenous temperature profile can be achieved. However, it puts higher demands on the gas manifolding than a cross-flow configuration does. The difference in stack size (power density) was substantial. Very low NOx emissions can be expected from a SOFC system employing a catalytic combustor for the unspent fuel. Also carbon dioxide emissions are lower than state of the art gas turbines and diesel engines. Although system performance and emissions are predicted to be extremely good, the road to success depends also on the installation cost. A short to medium term cost goal of 1000 USD/kW is within reach. (au)

  6. Proton conducting membranes for high temperature fuel cells with solid state water free membranes

    Science.gov (United States)

    Narayanan, Sekharipuram R. (Inventor); Yen, Shiao-Pin S. (Inventor)

    2006-01-01

    A water free, proton conducting membrane for use in a fuel cell is fabricated as a highly conducting sheet of converted solid state organic amine salt, such as converted acid salt of triethylenediamine with two quaternized tertiary nitrogen atoms, combined with a nanoparticulate oxide and a stable binder combined with the converted solid state organic amine salt to form a polymeric electrolyte membrane. In one embodiment the membrane is derived from triethylenediamine sulfate, hydrogen phosphate or trifiate, an oxoanion with at least one ionizable hydrogen, organic tertiary amine bisulfate, polymeric quaternized amine bisulfate or phosphate, or polymeric organic compounds with quaternizable nitrogen combined with Nafion to form an intimate network with ionic interactions.

  7. Modelling of tubular-designed solid oxide fuel cell with indirect internal reforming operation fed by different primary fuels

    Science.gov (United States)

    Dokmaingam, P.; Assabumrungrat, S.; Soottitantawat, A.; Laosiripojana, N.

    Mathematical models of an indirect internal reforming solid oxide fuel cell (IIR-SOFC) fed by four different primary fuels, i.e., methane, biogas, methanol and ethanol, are developed based on steady-state, heterogeneous, two-dimensional and tubular-design SOFC models. The effect of fuel type on the thermal coupling between internal endothermic reforming with exothermic electrochemical reactions and system performance are determined. The simulation reveals that an IIR-SOFC fuelled by methanol provides the smoothest temperature gradient with high electrochemical efficiency. Furthermore, the content of CO 2 in biogas plays an important role on system performance since electrical efficiency is improved by the removal of some CO 2 from biogas but a larger temperature gradient is expected. Sensitivity analysis of three parameters, namely, a operating pressure, inlet steam to carbon (S:C) ratio and flow direction is then performed. By increasing the operating pressure up to 10 bar, the system efficiency increases and the temperature gradient can be minimized. The use of a high inlet S:C ratio reduces the cooling spot at the entrance of reformer channel but the electrical efficiency is considerably decreased. An IIR-SOFC with a counter-flow pattern (as based case) is compared with that with co-flow pattern (co-flow of air and fuel streams through fuel cell). The IIR-SOFC with co-flow pattern provides higher voltage and a smoother temperature gradient along the system due to superior matching between heat supplied from electrochemical reaction and heat required for steam reforming reaction; thus it is expected to be a better option for practical applications.

  8. Numerical solution of moving boundary problem for deposition process in solid fuel gas generator

    Science.gov (United States)

    Volokhov, V. M.; Dorofeenko, S. O.; Sharov, M. S.; Toktaliev, P. D.

    2016-11-01

    Moving boundary problem in application to process of depositions formation in gas generator are considered. Gas generator, as a part of fuel preparation system of high-speed vehicle, convert solid fuel into multicomponent multiphase mixture, which further burned down in combustion chamber. Mathematical model of two-phase “gas-solid particles” flow, including Navier-Stokes equations for turbulent flow in gas generator and mass, impulse conservations laws for elementary depositions layer are proposed. Verification of proposed mathematical model for depositions mass in gas generator conditions is done. Further possible improvements of proposed model, based on more detail accounting of particle-wall interaction and wall's surface adhesion properties are analyzed.

  9. Tubular solid oxide fuel cells with porous metal supports and ceramic interconnections

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Kevin [Export, PA; Ruka, Roswell J [Pittsburgh, PA

    2012-05-08

    An intermediate temperature solid oxide fuel cell structure capable of operating at from 600.degree. C. to 800.degree. C. having a very thin porous hollow elongated metallic support tube having a thickness from 0.10 mm to 1.0 mm, preferably 0.10 mm to 0.35 mm, a porosity of from 25 vol. % to 50 vol. % and a tensile strength from 700 GPa to 900 GPa, which metallic tube supports a reduced thickness air electrode having a thickness from 0.010 mm to 0.2 mm, a solid oxide electrolyte, a cermet fuel electrode, a ceramic interconnection and an electrically conductive cell to cell contact layer.

  10. Air-Independent Solid Oxide Fuel Cells for NASA's LOX-CH4 Landers

    Science.gov (United States)

    Ryan, Abigail C.; Araghi, Koorosh R.; Farmer, Serene C.

    2013-01-01

    Gemini, Apollo, and Space Shuttle used fuel cells as main power source for vehicle and water source for life support and thermal PEM (Gemini) and Alkaline (Apollo, Shuttle) fuel cells were used Ideal for short (less than 3 weeks) missions when the required O2 and H2 can be launched with the vehicle. New missions that might require long-duration stays in orbit or at a habitat, cannot rely on the availability of pure reactants but should also aim to be sun-independent - a problem for which Solid Oxide Fuel Cells might be the answer. Recently, NASA has investigated & developed LOX/CH4-propelled landers (Altair, MORPHEUS). In order to preserve mission flexibility, fuel cells are being studied as a potential power source. Much of NASA's fuel cell development has been focused on creating a dead-headed, non-flow through PEM fuel cells which would weigh less and be more reliable than the existing Alkaline and PEM technology; however, LOX/CH4 as a propellant introduces SOFCs as a power option due to their ability to accept those reactants without much reforming.

  11. Occurrence of bromine in fluidised bed combustion of solid recovered fuel

    Energy Technology Data Exchange (ETDEWEB)

    Vainikka, P.

    2011-12-15

    Corrosive ash species are the single most important factor limiting the electric efficiency of steam boiler plants fired with waste or biomass. Chlorine has been found to have a central role in the chemistry involved as it reduces the melting temperature of ash, forms corrosive vapour and gas species in the furnace and halogenated deposits on boiler heat transfer surfaces. In this context chlorine has been extensively researched. At the time of writing this thesis there was hardly any published data available on the occurrence of bromine (Br) in the aforementioned context. The objective of this work was to review the occurrence of bromine in solid fuels and characterise the behaviour of bromine in full-scale fluidised bed combustion. The review on the occurrence of bromine in solid fuels revealed that in anthropogenic wastes bromine is mainly found in connection to flame retarded substances. Several weight percentages of bromine can be found in plastics treated with brominated flame retardants (BFRs). Bromine is typically found some 100-200 mg kg-1 in mixed municipal solid wastes (MSW). Bromine may be enriched in fuels with high share of plastics, such as solid recovered fuel (SRF) or refuse derived fuel (RDF). Up to 2000 mg kg-1 was found as a monthly average in SRF, typical levels being 20-200 mg kg-1. Wastewater sludge from paper mills may contain bromine 20-100 mg kg-1 due the use of bromine based biocides. In other fuels bromine may be found in significant amounts in marine influenced coal deposits and peat as well as in biomass treated with brominated pesticides. In the experimental part SRF, spruce bark and wastewater sludge from a paper mill were co-fired in a full- scale bubbling fluidised bed (BFB) boiler, and the collected fuels, aerosols and waterwall deposits were analysed with the focus on the fate of bromine. Bromine was mainly found to form water soluble high vapour pressure alkali metal halides in the furnace - in the form of KBr(g) and NaBr(g) as

  12. Spray pyrolysis of doped-ceria barrier layers for solid oxide fuel cells

    DEFF Research Database (Denmark)

    Szymczewska, Dagmara; Chrzan, Aleksander; Karczewski, Jakub

    2017-01-01

    Gadolinium doped ceria (Ce0.8Gd0.2O2 − x-CGO) layer fabricated by spray pyrolysis is investigated as the diffusion barrier for solid oxide fuel cell. It is deposited between the La0.6Sr0.4FeO3 − δ cathode and the yttria stabilized zirconia electrolyte to mitigate harmful interdiffusion o...

  13. Physical Properties of Mixed Conductor Solid Oxide Fuel Cell Anodes of Doped CeO2

    DEFF Research Database (Denmark)

    Mogensen, Mogens Bjerg; Lindegaard, Thomas; Hansen, Uffe Rud

    1994-01-01

    Samples of CeO2 doped with oxides such as CaO and Gd2O3 were prepared. Their conductivities and expansions onreduction were measured at 1000°C, and the thermal expansion coefficients in the range 50 to 1000°C were determined. Theionic and electronic conductivity were derived from curves of total ...... for solid oxide fuel cell anodes. Not all requirements are fulfilled. Measures to compensate for this arediscussed....

  14. Process Simulation of Biomass Gasification Integrated With a Solid Oxide Fuel Cell Stack

    OpenAIRE

    Doherty, Wayne; Reynolds, Anthony; Kennedy, David

    2014-01-01

    Biomass gasification-solid oxide fuel cell (BG-SOFC) combined heat and power (CHP) systems are of major interest in the context of climate change mitigation, energy security and increasing energy efficiency. Aspen Plus is employed to simulate various BG-SOFC CHP systems. The aim of the research work is to investigate the technical feasibility of these systems and to study the influence of important operating parameters and examine integration options. Systems based on dual fluidised bed steam...

  15. A novel electronic current-blocked stable mixed ionic conductor for solid oxide fuel cells

    NARCIS (Netherlands)

    Sun, Wenping; Jiang, Yinzhu; Wang, Yanfei; Fang, S.; Zhu, Zhiwen; Liu, Wei

    2011-01-01

    A novel ionic conductor, BaCe0.8Sm0.2O3−δ–Ce0.8Sm0.2O2−δ (BCS–SDC, weight ratio 1:1), is reported as an electrolyte material for solid oxide fuel cells (SOFCs). Homogeneous BCS–SDC composite powders are synthesized via a one-step gel combustion method. The BCS and SDC crystalline grains play a role

  16. A novel electronic current-blocked stable mixed ionic conductor for solid oxide fuel cells

    NARCIS (Netherlands)

    Sun, Wenping; Jiang, Yinzhu; Wang, Yanfei; Fang, S.; Zhu, Zhiwen; Liu, Wei

    2011-01-01

    A novel ionic conductor, BaCe0.8Sm0.2O3¿¿¿Ce0.8Sm0.2O2¿¿ (BCS¿SDC, weight ratio 1:1), is reported as an electrolyte material for solid oxide fuel cells (SOFCs). Homogeneous BCS¿SDC composite powders are synthesized via a one-step gel combustion method. The BCS and SDC crystalline grains play a role

  17. X-ray micro Laue diffraction tomography analysis of a solid oxide fuel cell

    OpenAIRE

    Ferreira Sanchez, D.; Villanova, J.; Laurencin, J.; Micha, J. S.; Montani, A.; Gergaud, P.; P. Bleuet

    2015-01-01

    International audience; The relevance of micro Laue diffraction tomography (mu-LT) to investigate heterogeneous polycrystalline materials has been studied. For this purpose, a multiphase solid oxide fuel cell (SOFC) electrode composite made of yttria-stabilized zirconia and nickel oxide phases, with grains of about a few micrometres in size, has been analyzed. In order to calibrate the Laue data and to test the technique's sensitivity limits, a monocrystalline germanium sample of about 8 x 4 ...

  18. Carbon and Redox Tolerant Infiltrated Oxide Fuel-Electrodes for Solid Oxide Cells

    DEFF Research Database (Denmark)

    Skafte, Theis Løye; Sudireddy, Bhaskar Reddy; Blennow, P.

    2016-01-01

    To solve issues of coking and redox instability related to the presence of nickel in typical fuel electrodes in solid oxide cells,Gd-doped CeO2 (CGO) electrodes were studied using symmetriccells. These electrodes showed high electro-catalytic activity, butlow electronic conductivity. When...... deposition in a CO/CO2-atmosphere, while none of the non-nickel cells catalyzed carbon.Stability towards redox cycles was also proven....

  19. Advances in medium and high temperature solid oxide fuel cell technology

    CERN Document Server

    Salvatore, Aricò

    2017-01-01

    In this book well-known experts highlight cutting-edge research priorities and discuss the state of the art in the field of solid oxide fuel cells giving an update on specific subjects such as protonic conductors, interconnects, electrocatalytic and catalytic processes and modelling approaches. Fundamentals and advances in this field are illustrated to help young researchers address issues in the characterization of materials and in the analysis of processes, not often tackled in scholarly books.

  20. Design and performance of tubular flat-plate solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Matsushima, T.; Ikeda, D.; Kanagawa, H. [NTT Integrated Information & Energy Systems Labs., Tokyo (Japan)] [and others

    1996-12-31

    With the growing interest in conserving the environmental conditions, much attention is being paid to Solid Oxide Fuel Cell (SOFC), which has high energy-conversion efficiency. Many organizations have conducted studies on tubular and flat type SOFCs. Nippon Telegraph and Telephone Corporation (NTT) has studied a combined tubular flat-plate SOFC, and already presented the I-V characteristics of a single cell. Here, we report the construction of a stack of this SOFC cell and successful generation tests results.

  1. Accelerated creep in solid oxide fuel cell anode supports during reduction

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lund; Makowska, Malgorzata Grazyna; Greco, Fabio

    2016-01-01

    To evaluate the reliability of solid oxide fuel cell (SOFC) stacks during operation, the stress field in the stack must be known. During operation the stress field will depend on time as creep processes relax stresses. The creep of reduced Ni-YSZ anode support at operating conditions has been stu...... of the stress field in a stack based on anode supported SOFCs. (C) 2016 Elsevier B.V. All rights reserved....

  2. Diffusion and Gas Conversion Analysis of Solid Oxide Fuel Cells at Loads via AC Impedance

    OpenAIRE

    Robert U. Payne; Ying Zhu; Zhu, Wenhua H.; Timper, Mark S.; Elangovan, S; Bruce J. Tatarchuk

    2011-01-01

    Impedance measurements were conducted under practical load conditions in solid oxide fuel cells of differing sizes. For a 2 cm2 button cell, impedance spectra data were separately measured for the anode, cathode, and total cell. Improved equivalent circuit models are proposed and applied to simulate each of measured impedance data. Circuit elements related to the chemical and physical processes have been added to the total-cell model to account for an extra relaxation process in the spectra n...

  3. Reduction of carbon monoxide emission from a solid-fuel thermo-accumulation furnace

    Directory of Open Access Journals (Sweden)

    Dakić Dragoljub

    2006-01-01

    Full Text Available Many households in Serbia, using electric thermo-accumulation furnaces for heating, have been forced to find an alternative solution, due to a significant increase in electricity prices during the last decade. A possible solution is replacing electric heating appliances with the solid fuel-fired ones. A prototype of a new concept of thermo-accumulation solid fuel-fired furnace has been developed to meet these growing needs, providing electricity saving together with considerable environmental benefits. Two strategies for reduction of carbon monoxide emission are examined in the paper: application of Pt/Al2O3 catalyst, in the form of 3 ± 0.3 mm spheres, providing further combustion of flue gases within the furnace, as well as an additional emission reduction by means of the air excess control. Experimental investigations of the catalyst influence on the conversion of carbon monoxide have been done for different operation regimes and positions of the catalyst. The paper presents selected results regarding carbon monoxide emission during wood and coal combustion. Investigations suggest a considerable effect of the catalyst and a strong influence of the catalyst position within the furnace to carbon monoxide emission reduction. In addition, experimental tests have been conducted to asses the effect of the air excess control in the furnace on carbon monoxide emission. The amount of combustion air, the flue gas flow rate, and the fuel feeding regime have been adjusted in order to keep the flue gas oxygen content in a relatively narrow range, thus obtaining controlled combustion conditions and lower carbon monoxide emission. In this way, the furnace has been made able to respond to the changes in heating needs, fuel quality and other parameters, which is advantageous in comparison with similar solid-fuel fired furnaces. .

  4. New methodology of preparation support for solid oxide fuel cells using different pore forming agent

    Energy Technology Data Exchange (ETDEWEB)

    Fiuza, Raigenis da P.; Guedes, Bruna C.F.; Silva, Marcos A. da; Carvalho, Luiz F.V. de; Boaventura, Jaime S. [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica; Pontes, Luiz A.M. [Universidade Federal da Bahia (EP/UFBA), Salvador, BA (Brazil). Escola Politecnica. Programa de Pos-Graduacao em Engenharia Quimica

    2008-07-01

    The development of environment-friendly energy sources has been of the most important scientific and technological area. Solid oxide fuel cells (SOFC) are very promising alternative for their ability to handle renewable fuels with low emissions and high efficiency. However, this device requires massive improvement before commercial application. This work studies the pore formation in the cell anode and cathode with NaHCO{sub 3} or citric acid, comparing to graphite. The three agents make pore with similar features, but the use of NaHCO{sub 3} and citric acid considerably improves the adhesion of the electrode-electrolyte interface, critical characteristic for good cell efficiency. The prepared anode-electrolyte-cathode structure was studied by SEM technique. The SOFC prepared using citric acid was tested with gaseous ethanol, natural gas and hydrogen. For all these three fuels the SOFC shows virtually no overpotential, indicating the good ionic conductance of the electrodes-electrolyte interface.. (author)

  5. A novel layered perovskite as symmetric electrode for direct hydrocarbon solid oxide fuel cells

    Science.gov (United States)

    Zhao, Ling; Chen, Kongfa; Liu, Yuanxu; He, Beibei

    2017-02-01

    Layered perovskite oxides are well known to possess significant electronic, magnetic and electrochemical properties. Herein, we highlight a novel layered perovskite PrBaMn1.5Fe0.5O5+δ (PBMFO) as electrodes of symmetrical solid oxide fuel cells (SSOFCs). The layered PBMFO shows high electrical conductivity of 112.5 and 7.4 S cm-1 at 800 °C in air and 5% H2/Ar, respectively. The single cell with PBMFO symmetric electrodes achieves peak power density of 0.54 W cm-2 at 800 °C using humidified hydrogen as fuel. Moreover, PBMFO electrodes demonstrate good redox stability and high coking tolerance against hydrocarbon fuel.

  6. LOW COST MULTI-LAYER FABRICATION METHOD FOR SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Christopher Milliken; Robert Ruhl; Jennifer Hillman

    2002-06-01

    Technology Management, Inc has evaluated the practical fabrication advantages and potential economic impact of a multi-pass screen printing process on the costs of fabricating planar solid oxide fuel cell stacks. During this program, multiple catalyzed binder systems were considered. Preliminary screening experiments resulted in four systems being selected for further evaluation. Inks were formulated using these binders in combination with at least three fuel cell materials (anode, cathode, and seal material). Reactivity of the binder with catalyst and fuel cell materials was evaluated. Cell tests indicated that the catalyzed binders did not negatively impact cell performance. Tests were conducted demonstrating single cell performance comparable with standard cell fabrication technology. Tailored patterns were also demonstrated. Economic evaluation indicated that a significant reduction in cost could be achieved, primarily through reduced capital equipment needs.

  7. Cost Study for Manufacturing of Solid Oxide Fuel Cell Power Systems

    Energy Technology Data Exchange (ETDEWEB)

    Weimar, Mark R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chick, Lawrence A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Gotthold, David W. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Whyatt, Greg A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2013-09-30

    Solid oxide fuel cell (SOFC) power systems can be designed to produce electricity from fossil fuels at extremely high net efficiencies, approaching 70%. However, in order to penetrate commercial markets to an extent that significantly impacts world fuel consumption, their cost will need to be competitive with alternative generating systems, such as gas turbines. This report discusses a cost model developed at PNNL to estimate the manufacturing cost of SOFC power systems sized for ground-based distributed generation. The power system design was developed at PNNL in a study on the feasibility of using SOFC power systems on more electric aircraft to replace the main engine-mounted electrical generators [Whyatt and Chick, 2012]. We chose to study that design because the projected efficiency was high (70%) and the generating capacity was suitable for ground-based distributed generation (270 kW).

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

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    steam in a HRSG (heat recovery steam generator). The bottoming steam cycle was modeled with two configurations: (1) a simple single pressure level and (2) a dual pressure level with both a reheat and a pre-heater. The SOFC stacks in the present SOFC-ST hybrid cycles were not pressurized. The dual......A SOFC (solid oxide fuel cell) cycle running on natural gas was integrated with a ST (steam turbine) cycle. The fuel is desulfurized and pre-reformed before entering the SOFC. A burner was used to combust the remaining fuel after the SOFC stacks. The off-gases from the burner were used to produce...... pressure configuration steam cycle combined with SOFC cycle (SOFC-ST) was new and has not been studied previously. In each of the configuration, a hybrid recuperator was used to recovery the remaining energy of the off-gases after the HRSG. Thus, four different plants system setups were compared to each...

  9. Microwave assisted sintering of gadolinium doped barium cerate electrolyte for intermediate temperature solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Arumugam Senthil, E-mail: senthu.ramp@gmail.com [Department of Physics, PSG College of Technology, Coimbatore, 641 004, Tamilnadu (India); Balaji, Ramamoorthy [Department of Physics, PSG College of Technology, Coimbatore, 641 004, Tamilnadu (India); Jayakumar, Srinivasalu [Department of Physics, PSG Institute of Technology and Applied Research, Coimbatore, 641 062, Tamilnadu (India); Pradeep, Chandran [Department of Physics, Indian Institute of Technology, Madras, 600 036, Tamilnadu (India)

    2016-10-01

    In Solid Oxide Fuel Cell (SOFC), electrolyte plays a vital role to increase the energy conversion efficiency. The main hurdle of such electrolyte in fuel cell is its higher operating temperature (1000 °C) which results in design limitation and higher fabrication cost. In order to reduce the operating temperature of SOFC, a suitable electrolyte has been prepared through co-precipitation method followed by microwave sintering of solid ceramic. The calcination temperature for the as-prepared powder was identified using Differential Scanning Calorimetry. The crystal structure of the sample was found to exhibit its orthorhombic perovskite structure. The particle size was determined using High-Resolution Transmission Electron Microscope with uniform in shape and size, match with XRD results and confirmed from structural analysis. Thus, the sample prepared via co-precipitation method and the solid ceramic sintered through microwave can be a promising electrolyte for fuel cells operated at intermediate temperature. - Highlights: • To synthesis the composite electrolyte by chemical method and sinter using microwave. • To reduce the operating temperature of electrolyte for high ionic conductivity in SOFC's. • To study the phase purity and to develop nanocomposite at reduced temperature.

  10. Design of an extrusion screw and solid fuel produced from coconut shell

    Directory of Open Access Journals (Sweden)

    Madhiyanon, T

    2006-03-01

    Full Text Available The objectives were to design an extrusion screw to produce biomass solid fuel in a cold extrusion process, and investigate the effects of molasses used as a selected adhesive on the physical properties of extruded products. The material employed consisted of crushed coconut shell char and coconut fiber char mixed at a ratio of 40:60. The ratios of molasses in the mixture were 10:100, 15:100 and 20:100 (by weight and the extrusion die angles were 1.0, 1.1, 1.2, and 1.3 degrees gradation per experiment. The experimental results showed that the newly designed screw could function properly in the output range 0.75-0.90 kg/min, which is close to the design value. Regarding the molasses's effect on solid fuel properties, increasing the share of molasses was positive for both output and strength of the resulting briquettes, whereas the results of increasing die angle showed decreases in both output and strength. The compressive strength varied between 2.49-2.87 MPa in all circumstances, which was considerably higher than acceptable industrial level. Furthermore, the extruded solid fuel showed excellent resistance to impact force. Regarding energy consumption, the amount of electrical energy used in the extrusion process was insignificant, ranging between 0.040-0.079 kWh/kg.

  11. Mathematical model of a plate fin heat exchanger operating under solid oxide fuel cell working conditions

    Science.gov (United States)

    Kaniowski, Robert; Poniewski, Mieczysław

    2013-12-01

    Heat exchangers of different types find application in power systems based on solid oxide fuel cells (SOFC). Compact plate fin heat exchangers are typically found to perfectly fit systems with power output under 5 kWel. Micro-combined heat and power (micro-CHP) units with solid oxide fuel cells can exhibit high electrical and overall efficiencies, exceeding 85%, respectively. These values can be achieved only when high thermal integration of a system is assured. Selection and sizing of heat exchangers play a crucial role and should be done with caution. Moreover, performance of heat exchangers under variable operating conditions can strongly influence efficiency of the complete system. For that reason, it becomes important to develop high fidelity mathematical models allowing evaluation of heat exchangers under modified operating conditions, in high temperature regimes. Prediction of pressure and temperatures drops at the exit of cold and hot sides are important for system-level studies. Paper presents dedicated mathematical model used for evaluation of a plate fin heat exchanger, operating as a part of micro-CHP unit with solid oxide fuel cells.

  12. A Methodology for Assessing the Sustainability of Hydrogen Production from Solid Fuels

    Directory of Open Access Journals (Sweden)

    Nirmal V. Gnanapragasam

    2010-05-01

    Full Text Available A methodology for assessing the sustainability of hydrogen production using solid fuels is introduced, in which three sustainability dimensions (ecological, sociological and technological are considered along with ten indicators for each dimension. Values for each indicator are assigned on a 10-point scale based on a high of 1 and a low of 0, depending on the characteristic of the criteria associated with each element or process, utilizing data reported in the literature. An illustrative example is presented to compare two solid fuels for hydrogen production: coal and biomass. The results suggest that qualitative sustainability indicators can be reasonably defined based on evaluations of system feasibility, and that adequate flexibility and comprehensiveness is provided through the use of ten indicators for each of the dimensions for every process or element involved in hydrogen production using solid fuels. Also, the assessment index values suggest that biomasses have better sustainability than coals, and that it may be advantageous to use coals in combination with biomass to increase their ecological and social sustainability. The sustainability assessment methodology can be made increasingly quantitative, and is likely extendable to other energy systems, but additional research and development is needed to lead to a more fully developed approach.

  13. TAPE CALENDERING MANUFACTURING PROCESS FOR MULTILAYER THIN-FILM SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen Minh; Kurt Montgomery

    2004-10-01

    This report summarizes the work performed by Hybrid Power Generation Systems, LLC during the Phases I and II under Contract DE-AC26-00NT40705 for the U. S. Department of Energy, National Energy Technology Laboratory (DOE/NETL) entitled ''Tape Calendering Manufacturing Process For Multilayer Thin-Film Solid Oxide Fuel Cells''. The main objective of this project was to develop the manufacturing process based on tape calendering for multilayer solid oxide fuel cells (SOFC's) using the unitized cell design concept and to demonstrate cell performance under specified operating conditions. Summarized in this report is the development and improvements to multilayer SOFC cells and the unitized cell design. Improvements to the multilayer SOFC cell were made in electrochemical performance, in both the anode and cathode, with cells demonstrating power densities of nearly 0.9 W/cm{sup 2} for 650 C operation and other cell configurations showing greater than 1.0 W/cm{sup 2} at 75% fuel utilization and 800 C. The unitized cell design was matured through design, analysis and development testing to a point that cell operation at greater than 70% fuel utilization was demonstrated at 800 C. The manufacturing process for both the multilayer cell and unitized cell design were assessed and refined, process maps were developed, forming approaches explored, and nondestructive evaluation (NDE) techniques examined.

  14. Development of solid oxide fuel cells; Desenvolvimento de celulas a combustivel do tipo oxido solido (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Boaventura, Jaime S.; Alencar, Marcelo Goncalves F. de; Amaral, Alexandre Alves do; Benedicto, Joao Paulo Santos; Silva, Marcos A. [Universidade Federal da Bahia (UFBA), Salvador, BA (Brazil). Inst. de Quimica. Dept. de Fisico-Quimica

    2006-07-01

    Fuel cells allow the energy production without the thermodynamic restriction of the conversion of heat into work. Among their various types, the solid oxide fuel cells (SOFC), operating at high temperatures, allow the methane conversion into electricity directly on the anode. The main element of the SOFC is the structure A/E/C: anode/electrolyte/cathode, all sintered at high temperature as resistant ceramic materials. Dense electrolyte (YSZ: zirconia stabilized for Yttria) separates the anode (Ni+Co/YSZ: cobalt promoted nickel, supported on YSZ) and cathode (LSM: strontium-doped lanthanum manganite), both with porosity obtained by graphite addition. To obtain suitable A/E/C pellets, the layer sintering with appropriate mechanical and textural characteristics is essential, requiring excellent electric junctions between them. The cell performance has been evaluated between 850 and 950 degree C, using hydrogen or methane fuel; the tension and current for different resistance values in the electrical circuit have been measured. The cobalt addition to the cell anode significantly increased its activity for the reform reaction. The beneficial effect was probably due to the easier nickel reduction in cobalt presence. This work had the objectives of developing and evaluating electro-catalysts, as well as the solid oxide fuel cells using these catalysts as anode. Five SOFC models (SOFC 1 to SOFC 5) are described; all of them were developed aiming at improving the preparation of the anode/electrolyte/cathode structure (A/E/C). (author)

  15. Military Solid Waste Reformer: A Pilot Study to Convert Military Waste to Logistics Fuel in the Field

    National Research Council Canada - National Science Library

    Myers, Duane

    2004-01-01

    The Military Solid Waste Reformer project was a laboratory validation of conventional gasification and/or pyrolysis processes for the conversion of military field waste to liquid fuels in the field...

  16. Models for solid oxide fuel cell systems exploitation of models hierarchy for industrial design of control and diagnosis strategies

    CERN Document Server

    Marra, Dario; Polverino, Pierpaolo; Sorrentino, Marco

    2016-01-01

    This book presents methodologies for optimal design of control and diagnosis strategies for Solid Oxide Fuel Cell systems. A key feature of the methodologies presented is the exploitation of modelling tools that balance accuracy and computational burden.

  17. Advanced manufacturing of intermediate temperature, direct methane oxidation membrane electrode assemblies for durable solid oxide fuel cell Project

    Data.gov (United States)

    National Aeronautics and Space Administration — ITN proposes to create an innovative anode supported membrane electrode assembly (MEA) for solid oxide fuel cells (SOFCs) that is capable of long-term operation at...

  18. Solid Oxide Fuel Cell/Turbine Hybrid Power System for Advanced Aero-propulsion and Power Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Solid oxide fuel cell (SOFC)/ gas turbine hybrid power systems (HPSs) have been recognized by federal agencies and other entities as having the potential to operate...

  19. Mutagenicity and Pollutant Emission Factors of Solid-Fuel Cookstoves: Comparison with Other Combustion Sources

    Science.gov (United States)

    Mutlu, Esra; Warren, Sarah H.; Ebersviller, Seth M.; Kooter, Ingeborg M.; Schmid, Judith E.; Dye, Janice A.; Linak, William P.; Gilmour, M. Ian; Jetter, James J.; Higuchi, Mark; DeMarini, David M.

    2016-01-01

    Background: Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects. Objective: We evaluated two categories of solid-fuel cookstoves for eight pollutant and four mutagenicity emission factors, correlated the mutagenicity emission factors, and compared them to those of other combustion emissions. Methods: We burned red oak in a 3-stone fire (TSF), a natural-draft stove (NDS), and a forced-draft stove (FDS), and we combusted propane as a liquified petroleum gas control fuel. We determined emission factors based on useful energy (megajoules delivered, MJd) for carbon monoxide, nitrogen oxides (NOx), black carbon, methane, total hydrocarbons, 32 polycyclic aromatic hydrocarbons, PM2.5, levoglucosan (a wood-smoke marker), and mutagenicity in Salmonella. Results: With the exception of NOx, the emission factors per MJd were highly correlated (r ≥ 0.97); the correlation for NOx with the other emission factors was 0.58–0.76. Excluding NOx, the NDS and FDS reduced the emission factors an average of 68 and 92%, respectively, relative to the TSF. Nevertheless, the mutagenicity emission factor based on fuel energy used (MJthermal) for the most efficient stove (FDS) was between those of a large diesel bus engine and a small diesel generator. Conclusions: Both mutagenicity and pollutant emission factors may be informative for characterizing cookstove performance. However, mutagenicity emission factors may be especially useful for characterizing potential health effects and should be evaluated in relation to health outcomes in future research. An FDS operated as intended by the manufacturer is safer than a TSF, but without adequate ventilation, it will still result in poor indoor air quality. Citation: Mutlu E, Warren SH, Ebersviller SM, Kooter IM, Schmid JE, Dye JA, Linak WP, Gilmour MI, Jetter

  20. Mutagenicity and Pollutant Emission Factors of Solid-Fuel Cookstoves: Comparison with Other Combustion Sources.

    Science.gov (United States)

    Mutlu, Esra; Warren, Sarah H; Ebersviller, Seth M; Kooter, Ingeborg M; Schmid, Judith E; Dye, Janice A; Linak, William P; Gilmour, M Ian; Jetter, James J; Higuchi, Mark; DeMarini, David M

    2016-07-01

    Emissions from solid fuels used for cooking cause ~4 million premature deaths per year. Advanced solid-fuel cookstoves are a potential solution, but they should be assessed by appropriate performance indicators, including biological effects. We evaluated two categories of solid-fuel cookstoves for eight pollutant and four mutagenicity emission factors, correlated the mutagenicity emission factors, and compared them to those of other combustion emissions. We burned red oak in a 3-stone fire (TSF), a natural-draft stove (NDS), and a forced-draft stove (FDS), and we combusted propane as a liquified petroleum gas control fuel. We determined emission factors based on useful energy (megajoules delivered, MJd) for carbon monoxide, nitrogen oxides (NOx), black carbon, methane, total hydrocarbons, 32 polycyclic aromatic hydrocarbons, PM2.5, levoglucosan (a wood-smoke marker), and mutagenicity in Salmonella. With the exception of NOx, the emission factors per MJd were highly correlated (r ≥ 0.97); the correlation for NOx with the other emission factors was 0.58-0.76. Excluding NOx, the NDS and FDS reduced the emission factors an average of 68 and 92%, respectively, relative to the TSF. Nevertheless, the mutagenicity emission factor based on fuel energy used (MJthermal) for the most efficient stove (FDS) was between those of a large diesel bus engine and a small diesel generator. Both mutagenicity and pollutant emission factors may be informative for characterizing cookstove performance. However, mutagenicity emission factors may be especially useful for characterizing potential health effects and should be evaluated in relation to health outcomes in future research. An FDS operated as intended by the manufacturer is safer than a TSF, but without adequate ventilation, it will still result in poor indoor air quality. Mutlu E, Warren SH, Ebersviller SM, Kooter IM, Schmid JE, Dye JA, Linak WP, Gilmour MI, Jetter JJ, Higuchi M, DeMarini DM. 2016. Mutagenicity and pollutant

  1. Ignition et oxydation des particules de combustible solide pulvérisé Ignition and Oxidation of Pulverized Solid Fuel

    Directory of Open Access Journals (Sweden)

    De Soete G. G.

    2006-11-01

    élais d'ignition ont été déterminés pour un grand nombre de combustibles solides de rang inférieur et supérieur (charbons, cokes, asphaltènes, suies, bois, graphite. L'étude de la vitesse expérimentale de la combustion hétérogène, notamment l'étude de la température apparente d'activation, et sa dépendance par rapport à la taille des particules et à la concentration d'oxygène, montre que, dans les conditions des essais, cette combustion est contrôlée par la désorption du CO et se déroule principalement en régime cinético-diffusionnel mixte. L'étude de la dépendance des délais d'ignition par rapport à la température, la taille des particules et la pression partielle d'oxygène, suggère que, pendant ces délais, les réactions se déroulent en régime cinétique pur et que le produit des réactions de désorption est principalement le CO. The heated-grid method is used to investigate the competition between (1 the devolatilization and subsequent oxidation of pyrolysis products and (2 the ignition of the solid matrix and its rapid combustion. A comparison between the instant of ignition and the start of pyrolysis is used to determine the range in which ignition of a pyrolyzable solid fuel of the whole coal ignitiontype (i. e. when ignition occurs before pyrolysis becomes measurable occurs as a function of temperature, particle size and oxygen concentration. The results suggest that this type of ignition might occur, as a general rule, under conditions involving pulverized solid fuels in industrial flames. In the case of whole coalignition, the rate of combustion of the solid matrix is inhibited during the period following ignition. This inhibition is due partly to the difficulty oxygen has of spreading through the pores during the discharge of pyrolysis products and partly to preferential oxygen consumption during the oxidation of pyrolysis products, mainly when this oxidation develops in the form of flames. t is only when pyrolysis ends that

  2. Energy and exergy analysis of an ethanol reforming process for solid oxide fuel cell applications.

    Science.gov (United States)

    Tippawan, Phanicha; Arpornwichanop, Amornchai

    2014-04-01

    The fuel processor in which hydrogen is produced from fuels is an important unit in a fuel cell system. The aim of this study is to apply a thermodynamic concept to identify a suitable reforming process for an ethanol-fueled solid oxide fuel cell (SOFC). Three different reforming technologies, i.e., steam reforming, partial oxidation and autothermal reforming, are considered. The first and second laws of thermodynamics are employed to determine an energy demand and to describe how efficiently the energy is supplied to the reforming process. Effect of key operating parameters on the distribution of reforming products, such as H2, CO, CO2 and CH4, and the possibility of carbon formation in different ethanol reformings are examined as a function of steam-to-ethanol ratio, oxygen-to-ethanol ratio and temperatures at atmospheric pressure. Energy and exergy analysis are performed to identify the best ethanol reforming process for SOFC applications. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Modelling of simple hybrid solid oxide fuel cell and gas turbine power plant

    Science.gov (United States)

    Chan, S. H.; Ho, H. K.; Tian, Y.

    This paper presents the work on a simple, natural gas-fed, hybrid solid oxide fuel cell-gas turbine (SOFC-GT) power-generation system. The system consists of an internal-reforming SOFC (IRSOFC) stack, a combustor, a GT, two compressors and three recuperators. Two case studies are conducted with particular attention on the effects of operating pressure and fuel flow-rate on the performance of the components and overall system. Results show that an internal-reforming hybrid SOFC-GT system can achieve an electrical efficiency of more than 60% and a system efficiency (including waste heat recovery for co-generation) of more than 80%. It is also found that increasing the operating pressure will improve the system efficiency, whereas increasing the fuel flow-rate (while keeping the fuel utilisation rate unchanged) causes the system efficiency to decrease. In the latter case, the increase in system fuel consumption is relatively higher which removes the benefit of increase in SOFC stack and turbine power output.

  4. Preparation and Evaluation of Multi-Layer Anodes of Solid Oxide Fuel Cell

    Science.gov (United States)

    Santiago, Diana; Farmer, Serene C.; Setlock, John A.

    2012-01-01

    The development of an energy device with abundant energy generation, ultra-high specific power density, high stability and long life is critical for enabling longer missions and for reducing mission costs. Of all different types of fuel cells, the solid oxide fuel cells (SOFC) is a promising high temperature device that can generate electricity as a byproduct of a chemical reaction in a clean way and produce high quality heat that can be used for other purposes. For aerospace applications, a power-to-weight of (is) greater than 1.0 kW/kg is required. NASA has a patented fuel cell technology under development, capable of achieving the 1.0 kW/kg figure of merit. The first step toward achieving these goals is increasing anode durability. The catalyst plays an important role in the fuel cells for power generation, stability, efficiency and long life. Not only the anode composition, but its preparation and reduction are key to achieving better cell performance. In this research, multi-layer anodes were prepared varying the chemistry of each layer to optimize the performance of the cells. Microstructure analyses were done to the new anodes before and after fuel cell operation. The cells' durability and performance were evaluated in 200 hrs life tests in hydrogen at 850 C. The chemistry of the standard nickel anode was modified successfully reducing the anode degradation from 40% to 8.4% in 1000 hrs and retaining its microstructure.

  5. DEVELOPMENT OF LOW-COST MANUFACTURING PROCESSES FOR PLANAR, MULTILAYER SOLID OXIDE FUEL CELL ELEMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Scott Swartz; Matthew Seabaugh; William Dawson; Harlan Anderson; Tim Armstrong; Michael Cobb; Kirby Meacham; James Stephan; Russell Bennett; Bob Remick; Chuck Sishtla; Scott Barnett; John Lannutti

    2004-06-12

    This report summarizes the results of a four-year project, entitled, ''Low-Cost Manufacturing Of Multilayer Ceramic Fuel Cells'', jointly funded by the U.S. Department of Energy, the State of Ohio, and by project participants. The project was led by NexTech Materials, Ltd., with subcontracting support provided by University of Missouri-Rolla, Michael A. Cobb & Co., Advanced Materials Technologies, Inc., Edison Materials Technology Center, Gas Technology Institute, Northwestern University, and The Ohio State University. Oak Ridge National Laboratory, though not formally a subcontractor on the program, supported the effort with separate DOE funding. The objective of the program was to develop advanced manufacturing technologies for making solid oxide fuel cell components that are more economical and reliable for a variety of applications. The program was carried out in three phases. In the Phase I effort, several manufacturing approaches were considered and subjected to detailed assessments of manufacturability and development risk. Estimated manufacturing costs for 5-kW stacks were in the range of $139/kW to $179/kW. The risk assessment identified a number of technical issues that would need to be considered during development. Phase II development work focused on development of planar solid oxide fuel cell elements, using a number of ceramic manufacturing methods, including tape casting, colloidal-spray deposition, screen printing, spin-coating, and sintering. Several processes were successfully established for fabrication of anode-supported, thin-film electrolyte cells, with performance levels at or near the state-of-the-art. The work in Phase III involved scale-up of cell manufacturing methods, development of non-destructive evaluation methods, and comprehensive electrical and electrochemical testing of solid oxide fuel cell materials and components.

  6. Modeling of gas turbine - solid oxide fuel cell systems for combined propulsion and power on aircraft

    Science.gov (United States)

    Waters, Daniel Francis

    This dissertation investigates the use of gas turbine (GT) engine integrated solid oxide fuel cells (SOFCs) to reduce fuel burn in aircraft with large electrical loads like sensor-laden unmanned air vehicles (UAVs). The concept offers a number of advantages: the GT absorbs many SOFC balance of plant functions (supplying fuel, air, and heat to the fuel cell) thereby reducing the number of components in the system; the GT supplies fuel and pressurized air that significantly increases SOFC performance; heat and unreacted fuel from the SOFC are recaptured by the GT cycle offsetting system-level losses; good transient response of the GT cycle compensates for poor transient response of the SOFC. The net result is a system that can supply more electrical power more efficiently than comparable engine-generator systems with only modest (Propulsion System Simulation (NPSS). A sensitivity analysis identifies important design parameters and translates uncertainties in model parameters into uncertainties in overall performance. GT-SOFC integrations reduce fuel burn 3-4% in 50 kW systems on 35 kN rated engines (all types) with overall uncertainty electric power (factors >3 in some cases) than generator-based systems before encountering turbine inlet temperature limits. Aerodynamic drag effects of engine-airframe integration are by far the most important limiter of the combined propulsion/electrical generation concept. However, up to 100-200 kW can be produced in a bypass ratio = 8, overall pressure ratio = 40 turbofan with little or no drag penalty. This study shows that it is possible to create cooperatively integrated GT-SOFC systems for combined propulsion and power with better overall performance than stand-alone components.

  7. Facile Synthesis of Highly Active and Robust Ni-Mo Bimetallic Electrocatalyst for Hydrocarbon Oxidation in Solid Oxide Fuel Cells

    NARCIS (Netherlands)

    Hua, B.; Li, M.; Zhang, Y.-Q.; Chen, J.; Sun, Y.-F.; Yan, N.; Li, J.; Luo, J.L.

    2016-01-01

    We report a novel Ni–Mo bimetallic alloy decorated with multimicrocrystals as an efficient anode catalyst for hydrocarbon-fueled solid oxide fuel cells (SOFCs). We show that these Ni–Mo bimetallic alloys are highly active, thermally stable, and sulfur/coke tolerant electrocatalysts for hydrocarbon

  8. Thermodynamic analysis of an integrated gasification solid oxide fuel cell plant combined with an organic Rankine cycle

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Rokni, Masoud; Larsen, Ulrik

    2013-01-01

    into a fixed bed gasification plant to produce syngas which fuels the combined solid oxide fuel cells e organic Rankine cycle system to produce electricity. More than a hundred fluids are considered as possible alternative for the organic cycle using non-ideal equations of state (or state-of-the-art equations...

  9. Characterization and quantification of uncertainty in solid oxide fuel cell hybrid power plants

    Science.gov (United States)

    Subramanyan, Karthik; Diwekar, Urmila M.

    Distributed power generation is one of the most powerful applications of fuel cell technology. Several types of configurations have been hypothesized and tested for these kinds of applications at the conceptual level, but hybrid power plants are one of the most efficient. These are designs that combine the fuel cell cycle with other thermodynamic cycles to provide higher efficiency. The power plant in focus is the high pressure (HP)-low pressure (LP) solid oxide fuel cells (SOFC)/steam turbine (ST)/gas turbine (GT) configuration which is a part of the vision-21 program, which is a new approach, the U.S. Department of Energy's (DOE's) Office of Fossil Energy has begun, for developing 21st century energy plants that would have virtually no environmental impact. The overall goal is to effectively eliminate—at competitive costs—environmental concerns associated with the use of fossil fuels, for producing electricity and transportation fuels. In this design, coal is gasified in an entrained bed gasifier and the syn-gas produced is cleaned in a transport bed desulfurizer and passed over to cascaded SOFC modules (at two pressure levels). This module is integrated with a reheat GT cycle. The heat of the exhaust from the GT cycle is used to convert water to steam, which is eventually used in a steam bottoming cycle. Since this hybrid technology is new and futuristic, the system level models used for predicting the fuel cells' performance and for other modules like the desulfurizer have significant uncertainties in them. Also, the performance curves of the SOFC would differ depending on the materials used for the anode, cathode and electrolyte. The accurate characterization and quantification of these uncertainties is crucial for the validity of the model predictions and hence is the main focus of this paper. This work performs a two-level uncertainty analysis of the fuel cell module: uncertainty associated with (1) model and (2) material used for anode, cathode and

  10. Enablers and barriers to large-scale uptake of improved solid fuel stoves: a systematic review.

    Science.gov (United States)

    Rehfuess, Eva A; Puzzolo, Elisa; Stanistreet, Debbi; Pope, Daniel; Bruce, Nigel G

    2014-02-01

    Globally, 2.8 billion people rely on household solid fuels. Reducing the resulting adverse health, environmental, and development consequences will involve transitioning through a mix of clean fuels and improved solid fuel stoves (IS) of demonstrable effectiveness. To date, achieving uptake of IS has presented significant challenges. We performed a systematic review of factors that enable or limit large-scale uptake of IS in low- and middle-income countries. We conducted systematic searches through multidisciplinary databases, specialist websites, and consulting experts. The review drew on qualitative, quantitative, and case studies and used standardized methods for screening, data extraction, critical appraisal, and synthesis. We summarized our findings as "factors" relating to one of seven domains-fuel and technology characteristics; household and setting characteristics; knowledge and perceptions; finance, tax, and subsidy aspects; market development; regulation, legislation, and standards; programmatic and policy mechanisms-and also recorded issues that impacted equity. We identified 31 factors influencing uptake from 57 studies conducted in Asia, Africa, and Latin America. All domains matter. Although factors such as offering technologies that meet household needs and save fuel, user training and support, effective financing, and facilitative government action appear to be critical, none guarantee success: All factors can be influential, depending on context. The nature of available evidence did not permit further prioritization. Achieving adoption and sustained use of IS at a large scale requires that all factors, spanning household/community and program/societal levels, be assessed and supported by policy. We propose a planning tool that would aid this process and suggest further research to incorporate an evaluation of effectiveness.

  11. Molecularly Engineered Azobenzene Derivatives for High Energy Density Solid-State Solar Thermal Fuels.

    Science.gov (United States)

    Cho, Eugene N; Zhitomirsky, David; Han, Grace G D; Liu, Yun; Grossman, Jeffrey C

    2017-03-15

    Solar thermal fuels (STFs) harvest and store solar energy in a closed cycle system through conformational change of molecules and can release the energy in the form of heat on demand. With the aim of developing tunable and optimized STFs for solid-state applications, we designed three azobenzene derivatives functionalized with bulky aromatic groups (phenyl, biphenyl, and tert-butyl phenyl groups). In contrast to pristine azobenzene, which crystallizes and makes nonuniform films, the bulky azobenzene derivatives formed uniform amorphous films that can be charged and discharged with light and heat for many cycles. Thermal stability of the films, a critical metric for thermally triggerable STFs, was greatly increased by the bulky functionalization (up to 180 °C), and we were able to achieve record high energy density of 135 J/g for solid-state STFs, over a 30% improvement compared to previous solid-state reports. Furthermore, the chargeability in the solid state was improved, up to 80% charged from 40% charged in previous solid-state reports. Our results point toward molecular engineering as an effective method to increase energy storage in STFs, improve chargeability, and improve the thermal stability of the thin film.

  12. Modeling of gas transport through a tubular solid oxide fuel cell and the porous anode layer

    Science.gov (United States)

    Izzo, John R.; Peracchio, Aldo A.; Chiu, Wilson K. S.

    A design model is a necessary tool to understand the gas transport phenomena that occurs in a tubular solid oxide fuel cell (SOFC). This paper describes a computational model, which studies the gas flow through an anode-supported tubular SOFC and the subsequent diffusion of gas through its porous anode. The model is a numerical solution for the gas flow through a plug flow reactor with a diffusion layer, which includes the activation, ohmic, and concentration polarizations. Gas diffusion is modeled using the dusty-gas equations which include Knudsen diffusion. Mercury intrusion porosimetry (MIP) is used to experimentally determine micro-structural parameters such as porosity, tortuosity and effective diffusion coefficients, which are used in the diffusion equations for the porous anode layer. It was found that diffusion in the anode plays a key role in the performance of a tubular SOFC. The concentration gradient of hydrogen and water results in a lower concentration of hydrogen and a higher concentration of water at the reactive triple phase boundary (TPB) than in the fuel stream which both lead to a lower cell voltage. The gas diffusion determines the limiting current density of the cell where a higher concentration drop of hydrogen results in a lower limiting current density. The model validates well with experimental data and is used to improve micro-tubular solid oxide fuel cell designs.

  13. Composite electrolyte with proton conductivity for low-temperature solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Raza, Rizwan, E-mail: razahussaini786@gmail.com [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Energy Technology, Royal Institute of Technology, KTH, Stockholm 10044 (Sweden); Ahmed, Akhlaq; Akram, Nadeem; Saleem, Muhammad; Niaz Akhtar, Majid; Ajmal Khan, M.; Abbas, Ghazanfar; Alvi, Farah; Yasir Rafique, M. [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Sherazi, Tauqir A. [Department of Chemistry, COMSATS Institute of Information Technology, Abbotabad 22060 (Pakistan); Shakir, Imran [Sustainable Energy Technologies (SET) center, College of Engineering, King Saud University, PO-BOX 800, Riyadh 11421 (Saudi Arabia); Mohsin, Munazza [Department of Physics, Lahore College for Women University, Lahore, 54000 (Pakistan); Javed, Muhammad Sufyan [Department of Physics, COMSATS Institute of Information Technology, Lahore 54000 (Pakistan); Department of Applied Physics, Chongqing University, Chongqing 400044 (China); Zhu, Bin, E-mail: binzhu@kth.se, E-mail: zhubin@hubu.edu.cn [Department of Energy Technology, Royal Institute of Technology, KTH, Stockholm 10044 (Sweden); Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Faculty of Physics and Electronic Science/Faculty of Computer and Information, Hubei University, Wuhan, Hubei 430062 (China)

    2015-11-02

    In the present work, cost-effective nanocomposite electrolyte (Ba-SDC) oxide is developed for efficient low-temperature solid oxide fuel cells (LTSOFCs). Analysis has shown that dual phase conduction of O{sup −2} (oxygen ions) and H{sup +} (protons) plays a significant role in the development of advanced LTSOFCs. Comparatively high proton ion conductivity (0.19 s/cm) for LTSOFCs was achieved at low temperature (460 °C). In this article, the ionic conduction behaviour of LTSOFCs is explained by carrying out electrochemical impedance spectroscopy measurements. Further, the phase and structure analysis are investigated by X-ray diffraction and scanning electron microscopy techniques. Finally, we achieved an ionic transport number of the composite electrolyte for LTSOFCs as high as 0.95 and energy and power density of 90% and 550 mW/cm{sup 2}, respectively, after sintering the composite electrolyte at 800 °C for 4 h, which is promising. Our current effort toward the development of an efficient, green, low-temperature solid oxide fuel cell with the incorporation of high proton conductivity composite electrolyte may open frontiers in the fields of energy and fuel cell technology.

  14. Electrochemical investigation of mixed metal oxide nanocomposite electrode for low temperature solid oxide fuel cell

    Science.gov (United States)

    Abbas, Ghazanfar; Raza, Rizwan; Ashfaq Ahmad, M.; Ajmal Khan, M.; Jafar Hussain, M.; Ahmad, Mukhtar; Aziz, Hammad; Ahmad, Imran; Batool, Rida; Altaf, Faizah; Zhu, Bin

    2017-10-01

    Zinc-based nanostructured nickel (Ni) free metal oxide electrode material Zn0.60/Cu0.20Mn0.20 oxide (CMZO) was synthesized by solid state reaction and investigated for low temperature solid oxide fuel cell (LTSOFC) applications. The crystal structure and surface morphology of the synthesized electrode material were examined by XRD and SEM techniques respectively. The particle size of ZnO phase estimated by Scherer’s equation was 31.50 nm. The maximum electrical conductivity was found to be 12.567 S/cm and 5.846 S/cm in hydrogen and air atmosphere, respectively at 600∘C. The activation energy of the CMZO material was also calculated from the DC conductivity data using Arrhenius plots and it was found to be 0.060 and 0.075 eV in hydrogen and air atmosphere, respectively. The CMZO electrode-based fuel cell was tested using carbonated samarium doped ceria composite (NSDC) electrolyte. The three layers 13 mm in diameter and 1 mm thickness of the symmetric fuel cell were fabricated by dry pressing. The maximum power density of 728.86 mW/cm2 was measured at 550∘C.

  15. Interactions of nickel/zirconia solid oxide fuel cell anodes with coal gas containing arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, C.A.; Marina, O.A.; Thomsen, E.C.; Edwards, D.J.; Cramer, C.D.; Coffey, G.W.; Pederson, L.R. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2009-09-05

    The performance of anode-supported and electrolyte-supported solid oxide fuel cells was investigated in synthetic coal gas containing 0-10 ppm arsenic at 700-800 C. Arsenic was found to interact strongly with nickel, resulting in the formation of nickel-arsenic solid solution, Ni{sub 5}As{sub 2} and Ni{sub 11}As{sub 8}, depending on temperature, arsenic concentration, and reaction time. For anode-supported cells, loss of electrical connectivity in the anode support was the principal mode of degradation, as nickel was converted to nickel arsenide phases that migrated to the surface to form large grains. Cell failure occurred well before the entire anode was converted to nickel arsenide, and followed a reciprocal square root of arsenic partial pressure dependence that is consistent with a diffusion-based rate-limiting step. Failure occurred more quickly with electrolyte-supported cells, which have a substantially smaller nickel inventory. For these cells, time to failure varied linearly with the reciprocal arsenic concentration. Failure occurred when arsenic reached the anode/electrolyte interface, though agglomeration of nickel reaction products may have also contributed. Test performed with nickel/zirconia coupons showed that arsenic was essentially completely captured in a narrow band near the fuel gas inlet. Arsenic concentrations of {proportional_to}10 ppb or less are estimated to result in acceptable rates of fuel cell degradation. (author)

  16. Elementary kinetic modelling applied to solid oxide fuel cell pattern anodes and a direct flame fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Vogler, Marcel

    2009-05-27

    In the course of this thesis a model for the prediction of polarisation characteristics of solid oxide fuel cells (SOFC) was developed. The model is based on an elementary kinetic description of electrochemical reactions and the fundamental conservation principles of mass and energy. The model allows to predict the current-voltage relation of an SOFC and offers ideal possibilities for model validation. The aim of this thesis is the identification of rate-limiting processes and the determination of the elementary pathway during charge transfer. The numerical simulation of experiments with model anodes allowed to identify a hydrogen transfer to be the most probable charge-transfer reaction and revealed the influence of diffusive transport. Applying the hydrogen oxidation kinetics to the direct flame fuel cell system (DFFC) showed that electrochemical oxidation of CO is possible based on the same mechanism. Based on the quantification of loss processes in the DFFC system, improvements on cell design, predicting 80% increase of efficiency, were proposed. (orig.)

  17. Advanced materials for solid oxide fuel cells: Hafnium-Praseodymium-Indium Oxide System

    Energy Technology Data Exchange (ETDEWEB)

    Bates, J.L.; Griffin, C.W.; Weber, W.J.

    1988-06-01

    The HfO/sub 2/-PrO/sub 1.83/-In/sub 2/O/sub 3/ system has been studied at the Pacific Northwest Laboratory to develop alternative, highly electrically conducting oxides as electrode and interconnection materials for solid oxide fuel cells. A coprecipitation process was developed for synthesizing single-phase, mixed oxide powders necessary to fabricate powders and dense oxides. A ternary phase diagram was developed, and the phases and structures were related to electrical transport properties. Two new phases, an orthorhombic PrInO/sub 3/ and a rhombohedral Hf/sub 2/In/sub 2/O/sub 7/ phase, were identified. The highest electronic conductivity is related to the presence of a bcc, In/sub 2/O/sub 3/ solid solution (ss) containing HfO/sub 2/ and PrO/sub 1.83/. Compositions containing more than 35 mol % of the In/sub 2/O/sub 3/ ss have electrical conductivities greater than 10/sup /minus/1/ (ohm-cm)/sup /minus/1/, and the two or three phase structures that contain this phase appear to exhibit mixed electronic-ionic conduction. The high electrical conductivities and structures similar to the Y/sub 2/O/sub 3/-stabilized ZrO/sub 2/(HfO/sub 2/) electrolyte give these oxides potential for use as cathodes in solid oxide fuel cells. 21 refs.

  18. Combustion characteristics and turbulence modeling of swirling reacting flow in solid fuel ramjet

    Science.gov (United States)

    Musa, Omer; Xiong, Chen; Changsheng, Zhou

    2017-10-01

    This paper reviews the historical studies have been done on the solid-fuel ramjet engine and difficulties associated with numerical modeling of swirling flow with combustible gases. A literature survey about works related to numerical and experimental investigations on solid-fuel ramjet as well as using swirling flow and different numerical approaches has been provided. An overview of turbulence modeling of swirling flow and the behavior of turbulence at streamline curvature and system rotation are presented. A new and simple curvature/correction factor is proposed in order to reduce the programming complexity of SST-CC turbulence model. Finally, numerical and experimental investigations on the impact of swirling flow on SFRJ have been carried out. For that regard, a multi-physics coupling code is developed to solve the problems of multi-physics coupling of fluid mechanics, solid pyrolysis, heat transfer, thermodynamics, and chemical kinetics. The connected-pipe test facility is used to carry out the experiments. The results showed a positive impact of swirling flow on SFRJ along with, three correlations are proposed.

  19. Thermodynamic simulation of biomass gas steam reforming for a solid oxide fuel cell (SOFC system

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-12-01

    Full Text Available This paper presents a methodology to simulate a small-scale fuel cell system for power generation using biomass gas as fuel. The methodology encompasses the thermodynamic and electrochemical aspects of a solid oxide fuel cell (SOFC, as well as solves the problem of chemical equilibrium in complex systems. In this case the complex system is the internal reforming of biomass gas to produce hydrogen. The fuel cell input variables are: operational voltage, cell power output, composition of the biomass gas reforming, thermodynamic efficiency, electrochemical efficiency, practical efficiency, the First and Second law efficiencies for the whole system. The chemical compositions, molar flows and temperatures are presented to each point of the system as well as the exergetic efficiency. For a molar water/carbon ratio of 2, the thermodynamic simulation of the biomass gas reforming indicates the maximum hydrogen production at a temperature of 1070 K, which can vary as a function of the biomass gas composition. The comparison with the efficiency of simple gas turbine cycle and regenerative gas turbine cycle shows the superiority of SOFC for the considered electrical power range.

  20. Engine-integrated solid oxide fuel cells for efficient electrical power generation on aircraft

    Science.gov (United States)

    Waters, Daniel F.; Cadou, Christopher P.

    2015-06-01

    This work investigates the use of engine-integrated catalytic partial oxidation (CPOx) reactors and solid oxide fuel cells (SOFCs) to reduce fuel burn in vehicles with large electrical loads like sensor-laden unmanned air vehicles. Thermodynamic models of SOFCs, CPOx reactors, and three gas turbine (GT) engine types (turbojet, combined exhaust turbofan, separate exhaust turbofan) are developed and checked against relevant data and source material. Fuel efficiency is increased by 4% and 8% in the 50 kW and 90 kW separate exhaust turbofan systems respectively at only modest cost in specific power (8% and 13% reductions respectively). Similar results are achieved in other engine types. An additional benefit of hybridization is the ability to provide more electric power (factors of 3 or more in some cases) than generator-based systems before encountering turbine inlet temperature limits. A sensitivity analysis shows that the most important parameters affecting the system's performance are operating voltage, percent fuel oxidation, and SOFC assembly air flows. Taken together, this study shows that it is possible to create a GT-SOFC hybrid where the GT mitigates balance of plant losses and the SOFC raises overall system efficiency. The result is a synergistic system with better overall performance than stand-alone components.

  1. Method for Making a Fuel Cell from a Solid Oxide Monolithic Framework

    Science.gov (United States)

    Cable, Thomas L. (Inventor); Sofie, Stephen W. (Inventor)

    2014-01-01

    The invention is a novel solid oxide fuel cell (SOFC) stack comprising individual bi-electrode supported fuel cells in which a thin electrolyte is supported between electrodes of essentially equal thickness. Individual cell units are made from graded pore ceramic tape that has been created by the freeze cast method followed by freeze drying. Each piece of graded pore tape later becomes a graded pore electrode scaffold that subsequent to sintering, is made into either an anode or a cathode by means of appropriate solution and thermal treatment means. Each cell unit is assembled by depositing of a thin coating of ion conducting ceramic material upon the side of each of two pieces of tape surface having the smallest pore openings, and then mating the coated surfaces to create an unsintered electrode scaffold pair sandwiching an electrolyte layer. The opposing major outer exposed surfaces of each cell unit is given a thin coating of electrically conductive ceramic, and multiple cell units are stacked, or built up by stacking of individual cell layers, to create an unsintered fuel cell stack. Ceramic or glass edge seals are installed to create flow channels for fuel and air. The cell stack with edge sealants is then sintered into a ceramic monolithic framework. Said solution and thermal treatments means convert the electrode scaffolds into anodes and cathodes. The thin layers of electrically conductive ceramic become the interconnects in the assembled stack.

  2. Production method of solid electrolyte fuel cell; Kotai denkaishitsu nenryo denchi no seizo hoho

    Energy Technology Data Exchange (ETDEWEB)

    Nagata, K.; Kuru, C.

    1995-09-05

    In the conventional cylindrical type laterally grooved solid electrolyte fuel cell (SOFC), the interconnector is thermally sprayed on the electrolyte. Since it is difficult to form a dense interconnector film by thermal spraying, the sealing film is applied underneath the interconnector to prevent the fuel gas from leaking. This invention solves the problem. The interconnector film is formed by means of thermal spraying on the substrate tube before film formation of fuel electrode and electrolyte on the substrate tube. Then it is heat-treated at 1300{degree}C for 2 hours to make the interconnector and the electrolyte dense at the same time. Since then the air electrode film is formed to complete the cylindrical type laterally grooved SOFC. This method can eliminate the sealing film, or the intermediate film, which is required in the conventional fuel cell structure. So that the production process can be simplified remarkably to reduce the production cost. In addition, the heat treatment stabilizes the physical properties of interconnector film. 2 figs.

  3. High temperature solid oxide fuel cell integrated with novel allothermal biomass gasification. Part II: Exergy analysis

    Science.gov (United States)

    Panopoulos, K. D.; Fryda, L.; Karl, J.; Poulou, S.; Kakaras, E.

    Biomass gasification derived gas is a renewable fuel, which can be used for SOFC applications. This work investigates the integration of a near atmospheric solid oxide fuel cell (SOFC) with a novel allothermal biomass steam gasification process into a combined heat and power (CHP) system of less than MW e range. Heat for steam gasification is supplied from SOFC depleted fuel in a fluidised bed (FB) combustor via high temperature sodium heat pipes. In the first paper, the integrated system was modelled in Aspen Plus™ and critical aspects for its feasibility were identified. The aim of this second part is the evaluation of the integrated system in exergy terms. Satisfying allothermal gasification heat demand is illustrated by examining each sub-process involved separately as well as combined. For a relatively low STBR = 0.6, the SOFC fuel utilisation for which the system operates under optimum conditions is U f = 0.7. Above that value additional biomass has to be used in the FB combustor to provide gasification heat with considerable exergy losses. For SOFC operation at current density 2500 A m -2, the system uses 90 kg h -1 biomass, operates with electrical exergetic efficiency 32% producing 140 kW e, while the combined electrical and thermal exergetic efficiency is 35%.

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

    Science.gov (United States)

    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. Innovative Household Systems Based on Solid Oxide Fuel Cells for a Northern European climate

    DEFF Research Database (Denmark)

    Rokni, Masoud; Vialetto, Giulio

    2015-01-01

    Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence and to increase the use of renewable energies. In the last several years, new technologies have been developed, and some...... of them received subsidies to increase installation and reduce cost.This article presents an innovative cogeneration system based on a solid oxide fuel cell (SOFC) systemand heat pump for household applications with a focus on primary energy and economic savings using electric equivalent load parameter...... which is a function of the electricity and heat demand of the user, and allows different operation strategies to be considered. The proposal is to maximize the efficiency of the system and to make it profitable, even though technologies with a high purchase cost are considered.Simulations of the system...

  6. Residential Systems Based on Solid Oxide Fuel Cells for Scandinavian Climate

    DEFF Research Database (Denmark)

    Rokni, Masoud; Vialetto, Giulio

    2015-01-01

    Energy saving is an open point in most European countries where energy policies are oriented to reduce the use of fossil fuels, greenhouses emissions and energy independence and to increase the use of renewable energies. In the last several years, new technologies have been developed, and some...... of them received subsidies to increase installation and reduce cost. This article presents an innovative cogeneration system based on a solid oxide fuel cell (SOFC) system and heat pump for household applications with a focus on primary energy and economic savings using electric equivalent load parameter...... which is a function of the electricity and heat demand of the user, and allows different operation strategies to be considered. The proposal is to maximize the efficiency of the system and to make it profitable, even though technologies with a high purchase cost are considered. Simulations of the system...

  7. Materials and Components for Low Temperature Solid Oxide Fuel Cells – an Overview

    Directory of Open Access Journals (Sweden)

    D. Radhika

    2013-06-01

    Full Text Available This article summarizes the recent advancements made in the area of materials and components for low temperature solid oxide fuel cells (LT-SOFCs. LT-SOFC is a new trend in SOFCtechnology since high temperature SOFC puts very high demands on the materials and too expensive to match marketability. The current status of the electrolyte and electrode materials used in SOFCs, their specific features and the need for utilizing them for LT-SOFC are presented precisely in this review article. The section on electrolytes gives an overview of zirconia, lanthanum gallate and ceria based materials. Also, this review article explains the application of different anode, cathode and interconnect materials used for SOFC systems. SOFC can result in better performance with the application of liquid fuels such methanol and ethanol. As a whole, this review article discusses the novel materials suitable for operation of SOFC systems especially for low temperature operation.

  8. Method for processing coal-enrichment waste with solid and volatile fuel inclusions

    Science.gov (United States)

    Khasanova, A. V.; Zhirgalova, T. B.; Osintsev, K. V.

    2017-10-01

    The method relates to the field of industrial heat and power engineering. It can be used in coal preparation plants for processing coal waste. This new way is realized to produce a loose ash residue directed to the production of silicate products and fuel gas in rotary kilns. The proposed method is associated with industrial processing of brown coal beneficiation waste. Waste is obtained by flotation separation of rock particles up to 13 mm in size from coal particles. They have in their composition both solid and volatile fuel inclusions (components). Due to the high humidity and significant rock content, low heat of combustion, these wastes are not used on energy boilers, they are stored in dumps polluting the environment.

  9. Fabrication and characterization of a cathode-supported tubular solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chunhua; Liu, Renzhu; Wang, Shaorong; Wang, Zhenrong; Qian, Jiqin; Wen, Tinglian [CAS Key Laboratory of Materials for Energy Conversion, Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS), 1295 Dingxi Road, Shanghai 200050 (China)

    2009-07-15

    A cathode-supported tubular solid oxide fuel cell (CTSOFC) with the length of 6.0 cm and outside diameter of 1.0 cm has been successfully fabricated via dip-coating and co-sintering techniques. A crack-free electrolyte film with a thickness of {proportional_to}14 {mu}m was obtained by co-firing of cathode/cathode active layer/electrolyte/anode at 1250 C. The relative low densifying temperature for electrolyte was attributed to the large shrinkage of the green tubular which assisted the densification of electrolyte. The assembled cell was electrochemically characterized with humidified H{sub 2} as fuel and O{sub 2} as oxidant. The open circuit voltages (OCV) were 1.1, 1.08 and 1.06 V at 750, 800 and 850 C, respectively, with the maximum power densities of 157, 272 and 358 mW cm{sup -2} at corresponding temperatures. (author)

  10. Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

    DEFF Research Database (Denmark)

    Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

    2015-01-01

    State-of-the-art (SoA) solid oxide fuel cell (SOFC) stacks are tested using profiles relevant for use in micro combined heat and power (CHP) units. Such applications are characterised by dynamic load profiles. In order to shorten the needed testing time and to investigate potential acceleration...... of degradation, the profiles are executed faster than required for real applications. Operation with fast load cycling, both using hydrogen and methane/steam as fuels, does not accelerate degradation compared to constant operation, which demonstrates the maturity of SoA stacks and enables transferring knowledge...... from testing at constant conditions to dynamic operation. 7.5 times more cycles than required for 80,000 h lifetime as micro CHP are achieved on one-cell-stack level. The results also suggest that degradation mechanisms that proceed on a longer time-scale, such as creep, might have a more dominating...

  11. A Review of RedOx Cycling of Solid Oxide Fuel Cells Anode

    Science.gov (United States)

    Faes, Antonin; Hessler-Wyser, Aïcha; Zryd, Amédée; Van Herle, Jan

    2012-01-01

    Solid oxide fuel cells are able to convert fuels, including hydrocarbons, to electricity with an unbeatable efficiency even for small systems. One of the main limitations for long-term utilization is the reduction-oxidation cycling (RedOx cycles) of the nickel-based anodes. This paper will review the effects and parameters influencing RedOx cycles of the Ni-ceramic anode. Second, solutions for RedOx instability are reviewed in the patent and open scientific literature. The solutions are described from the point of view of the system, stack design, cell design, new materials and microstructure optimization. Finally, a brief synthesis on RedOx cycling of Ni-based anode supports for standard and optimized microstructures is depicted. PMID:24958298

  12. Optimization design of electrodes for anode-supported solid oxide fuel cells via genetic algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Shi, J.; Xue, X.

    2011-01-01

    Porous electrode is the critical component of solid-oxide fuel cells (SOFCs) and provides a functional material backbone for multi-physicochemical processes. Model based electrode designs could significantly improve SOFC performance. This task is usually performed via parameter studies for simple case and assumed property distributions for graded electrodes. When nonlinearly coupled multiparameters of electrodes are considered, it could be very difficult for the model based parameter study method to effectively and systematically search the design space. In this research, the optimization approach with a genetic algorithm is demonstrated for this purpose. An anode-supported proton conducting SOFC integrated with a fuel supply system is utilized as a physical base for the model development and the optimization design. The optimization results are presented, which are difficult to obtain for parametric study method.

  13. An experimental investigation of solid oxide fuel cell performance at variable operating conditions

    Directory of Open Access Journals (Sweden)

    Tikiz Ismet

    2016-01-01

    Full Text Available Cell temperature and selection of the reactant gases are crucial parameters for the design and optimization of fuel cell performance. In this study, effect of operating conditions on the performance of Solid Oxide Fuel (SOFC has been investigated. Application of Response Surface Methodology (RSM was applied to optimize operations conditions in SOFC. For this purpose, an experimental set up for testing of SOFC has been established to investigate the effect of Hydrogen, Oxygen, Nitrogen flow rates and cell temperature parameters on cell performance. Hydrogen flow rate, oxygen flow rate, nitrogen flow rate and cell temperature were the main parameters considered and they were varied between 0.25 and 1 L/min, 0.5 and 1 L/min, 0 and 1 L/min and 700-800 oC in the analyses respectively. The maximum power density was found as 0.572 W/cm2 in the experiments.

  14. Computer Simulations of Composite Electrodes in Solid-Oxide Fuel-Cells

    Energy Technology Data Exchange (ETDEWEB)

    Sunde, Svein

    1999-07-01

    Fuel cells are devices for converting the combined chemical (free) energy of fuels and oxygen (air) directly to electrical energy without relying on the dynamic action of steam heated by reacting fuel-oxygen mixtures, like in steam turbines, or of the reacting gas mixtures themselves, like in gas turbines. The basic rationale for fuel cells is their high efficiencies as compared to indirect-conversion methods. Fuel cells are currently being considered for a number of applications, among them de-centralised power supply. Fuel cells come in five basic types and are usually classified according to the type of electrolyte used, which in turn to a significant degree limits the options for anode and cathode materials. The solid-oxide fuel-cell (SOFC) , with which this thesis is concerned, is thus named after its oxide electrolyte, typically the oxide-ion conducting material yttria-stabilised zirconia (YSZ). While the cathode of an SOFC is often uniform in chemical composition (or at least intended to be), various problems of delamination, cracking etc. associated with the use of metallic anode electrocatalysts led to the development of composite SOFC anodes. Porous anodes consisting of Ni and YSZ particles in roughly 50/50 wt-% mixtures are now almost standard with any SOFC-development programme. The designer of composite SOFC electrodes is faced with at least three, interrelated questions: (1) What will be the optimum microstructure and composition of the composite electrode? (2) If the structure changes during operation, as is often observed, what will be the consequences for the internal losses in the cell? (3) How do we interpret electrochemical and conductivity measurements with regard to structure and composition? It is the primary purpose of this thesis to provide a framework for modelling the electrochemical and transport properties of composite electrodes for SOFC, and to arrive at some new insights that cannot be offered by experiment alone. Emphasis is put on

  15. Experimental study on the 300W class planar type solid oxide fuel cell stack: Investigation for appropriate fuel provision control and the transient capability of the cell performance

    Science.gov (United States)

    Komatsu, Y.; Brus, G.; Kimijima, S.; Szmyd, J. S.

    2012-11-01

    The present paper reports the experimental study on the dynamic behavior of a solid oxide fuel cell (SOFC). The cell stack consists of planar type cells with standard power output 300W. A Major subject of the present study is characterization of the transient response to the electric current change, assuming load-following operation. The present studies particularly focus on fuel provision control to the load change. Optimized fuel provision improves power generation efficiency. However, the capability of SOFC must be restricted by a few operative parameters. Fuel utilization factor, which is defined as the ratio of the consumed fuel to the supplied fuel is adopted for a reference in the control scheme. The fuel flow rate was regulated to keep the fuel utilization at 50%, 60% and 70% during the current ramping. Lower voltage was observed with the higher fuel utilization, but achieved efficiency was higher. The appropriate mass flow control is required not to violate the voltage transient behavior. Appropriate fuel flow manipulation can contribute to moderate the overshoot on the voltage that may appear to the current change. The overshoot on the voltage response resulted from the gradual temperature behavior in the SOFC stack module.

  16. Design and Optimization of an Integrated Biomass Gasification and Solid Oxide Fuel Cell System

    DEFF Research Database (Denmark)

    Bang-Møller, Christian

    . The work deals with the coupling of thermal biomass gasification and solid oxide fuel cells (SOFCs), and specific focus is kept on exploring the potential performance of hybrid CHP systems based on the novel two-stage gasification concept and SOFCs. The two-stage gasification concept is developed......-level modelling study of three conceptual plant designs based on two-stage gasification of wood chips with a thermal biomass input of ~0.5 MWth (LHV) is presented. Product gas is converted in a micro gas turbine (MGT) in the first plant design, in SOFCs in the second, and in a combined SOFC-MGT arrangement...

  17. Percolation theory to predict effective properties of solid oxide fuel-cell composite electrodes

    Science.gov (United States)

    Chen, Daifen; Lin, Zijing; Zhu, Huayang; Kee, Robert J.

    A micromodel based upon percolation theory is developed to predict effective properties in composite electrodes for solid oxide fuel-cell (SOFC) applications. The theory considers binary and multi-component mixtures of particles that are either ion or electron conductors. The model predicts effective ionic and electronic conductivities, three-phase boundary lengths, and hydraulic pore radii. The effective properties depend upon primary physical characteristics, including average particle-radii, volumetric packing densities, particle contact angles, and porosity. All results are presented in nondimensional form, which provides considerable generality in their practical application.

  18. Methane Steam Reforming over an Ni-YSZ Solid Oxide Fuel Cell Anode in Stack Configuration

    DEFF Research Database (Denmark)

    Mogensen, David; Grunwaldt, Jan-Dierk; Hendriksen, Peter Vang

    2014-01-01

    The kinetics of catalytic steam reforming of methane over an Ni-YSZ anode of a solid oxide fuel cell (SOFC) have been investigated with the cell placed in a stack configuration. In order to decrease the degree of conversion, a single cell stack with reduced area was used. Measurements were...... performed in the temperature range 600-800 degrees C and the partial pressures of all reactants and products were varied. The obtained rates could be well fitted with a power law expression (r proportional to P-CH4(0.7)). A simple model is presented which is capable of predicting the methane conversion...

  19. Ni-YSZ solid oxide fuel cell anode behavior upon redox cycling based on electrical characterization

    DEFF Research Database (Denmark)

    Klemensø, Trine; Mogensen, Mogens Bjerg

    2007-01-01

    Nickel (Ni)—yttria-stabilized zirconia (YSZ) cermets are a prevalent material used for solid oxide fuel cells. The cermet degrades upon redox cycling. The degradation is related to microstructural changes, but knowledge of the mechanisms has been limited. Direct current conductivity measurements...... were performed on cermets and cermets where the Ni component was removed. Measurements were carried out before, during, and after redox cycling the cermet. The cermet conductivity degraded over time due to sintering of the nickel phase. Following oxidizing events, the conductivity of the cermets...

  20. A combined SEM and CV Study of Solid Oxide Fuel Cell Interconnect Steels

    DEFF Research Database (Denmark)

    Kammer Hansen, Kent; Ofoegbu, Stanley; Mikkelsen, Lars

    2012-01-01

    Scanning electron microscopy and cyclic voltammetry were used to investigate the high temperature oxidation behavior of two solid oxide fuel cell interconnect steels. One alloy had a low content of manganese; the other alloy had a high content of manganese. Four reduction and four oxidation peaks...... were observed in the voltammograms of the low manganese alloy at a temperature of 800 oC. The voltammograms of the alloy with a high content of manganese were different. At 600 oC three reduction peaks and two oxidation peaks were observed. At 800 oC additional peaks were observed in the voltammogram...... for this alloy....

  1. Transient deformational properties of high temperature alloys used in solid oxide fuel cell stacks

    DEFF Research Database (Denmark)

    Tadesse Molla, Tesfaye; Kwok, Kawai; Frandsen, Henrik Lund

    2017-01-01

    Stresses and probability of failure during operation of solid oxide fuel cells (SOFCs) is affected by the deformational properties of the different components of the SOFC stack. Though the overall stress relaxes with time during steady state operation, large stresses would normally appear through...... transients in operation including temporary shut downs. These stresses are highly affected by the transient creep behavior of metallic components in the SOFC stack. This study investigates whether a variation of the so-called Chaboche's unified power law together with isotropic hardening can represent...... to describe the high temperature inelastic deformational behaviors of Crofer 22 APU used for metallic interconnects in SOFC stacks....

  2. Formation of Liquid Products at the Filtration Combustion of Solid Fuels

    Directory of Open Access Journals (Sweden)

    E. A. Salgansky

    2016-01-01

    Full Text Available Yields of liquid and gaseous products of the filtration combustion of cellulose, wood, peat, coal, and rubber have been investigated. Experiments have shown that the gasification of solid fuels in the regime with superadiabatic heating yields liquid hydrocarbons with quantity and quality, which are close to those produced using other methods, for example, by pyrolysis. But in this case no additional energy supply is needed to carry out the gasification process. The low calorific combustible gas, which forms in this process, contains a substantial quantity of carbon monoxide and hydrogen, which are components of syngas.

  3. AN ENGINEERING TEST USEFUL IN DEVELOPING GLASS SEALS FOR PLANAR SOLID OXIDE FUEL CELLS

    Energy Technology Data Exchange (ETDEWEB)

    Weil, K. Scott; Deibler, John E.; Hardy, John S.; Kim, Dong-Sang; Xia, Gordon; Coyle, Christopher A.

    2005-03-01

    Developing reliable, hermetic ceramic-to-metal seals has become a key issue to the future success of planar solid oxide fuel cell (pSOFC) technology. In the course of designing and fabricating operating pSOFC stacks at Pacific Northwest National Laboratory over the past several years, we have relied on a simple, but extremely useful seal testing technique that allows us to screen through the numerous variables involved in developing glass seals. Here we discuss the design of the test apparatus and the procedure we employed when using the test to analyze the effects of various processing parameters on the hermeticity and durability of our glass seals.

  4. Feed-forward control of a solid oxide fuel cell system with anode offgas recycle

    Science.gov (United States)

    Carré, Maxime; Brandenburger, Ralf; Friede, Wolfgang; Lapicque, François; Limbeck, Uwe; da Silva, Pedro

    2015-05-01

    In this work a combined heat and power unit (CHP unit) based on the solid oxide fuel cell (SOFC) technology is analysed. This unit has a special feature: the anode offgas is partially recycled to the anode inlet. Thus it is possible to increase the electrical efficiency and the system can be operated without external water feeding. A feed-forward control concept which allows secure operating conditions of the CHP unit as well as a maximization of its electrical efficiency is introduced and validated experimentally. The control algorithm requires a limited number of measurement values and few deterministic relations for its description.

  5. Rapid thermal cycling of metal-supported solid oxide fuel cellmembranes

    Energy Technology Data Exchange (ETDEWEB)

    Matus, Yuriy B.; De Jonghe, Lutgard C.; Jacobson, Craig P.; Visco, Steven J.

    2004-01-02

    Solid oxide fuel cell (SOFC) membranes were developed in which zirconia-based electrolyte thin films were supported by a composite metal/ceramic electrode, and were subjected to rapid thermal cycling between 200 and 800 C. The effects of this cycling on membrane performance were evaluated. The membranes, not yet optimized for performance, showed a peak power density of 350mW/cm2at 900 C in laboratory-sized SOFCs that was not affected by the thermal cycling. This resistance to cycling degradation is attributed to the close matching of thermal expansion coefficient of the cermet support electrode with that of the zirconia electrolyte.

  6. Production of Solid Fuel by Torrefaction Using Coconut Leaves As Renewable Biomass

    Directory of Open Access Journals (Sweden)

    Lola Domnina Bote Pestaño

    2016-11-01

    Full Text Available The reserves of non-renewable energy sources such as coal, crude oil and natural gas are not limitless, they gradually get exhausted and their price continually increases. In the last four decades, researchers have been focusing on alternate fuel resources to meet the ever increasing energy demand and to avoid dependence on crude oil. Amongst different sources of renewable energy, biomass residues hold special promise due to their inherent capability to store solar energy and amenability to subsequent conversion to convenient solid, liquid and gaseous fuels. At present, among the coconut farm wastes such as husks, shell, coir dust and coconut leaves, the latter is considered the most grossly under-utilized by in situ burning in the coconut farm as means of disposal. In order to utilize dried coconut leaves and to improve its biomass properties, this research attempts to produce solid fuel by torrefaction using dried coconut leaves for use as alternative source of energy. Torrefaction is a thermal method for the conversion of biomass operating in the low temperature range of 200oC-300oC under atmospheric conditions in absence of oxygen. Dried coconut leaves were torrefied at different feedstock conditions. The key torrefaction products were collected and analyzed. Physical and combustion characteristics of both torrefied and untorrefied biomass were investigated. Torrefaction of dried coconut leaves significantly improved the heating value compared to that of the untreated biomass.  Proximate compositions of the torrefied biomass also improved and were comparable to coal. The distribution of the products of torrefaction depends highly on the process conditions such as torrefaction temperature and residence time. Physical and combustion characteristics of torrefied biomass were superior making it more suitable for fuel applications. Article History: Received June 24th 2016; Received in revised form August 16th 2016; Accepted 27th 2016; Available

  7. Diffusion of Nickel into Ferritic Steel Interconnects of Solid Oxide Fuel/Electrolysis Stacks

    DEFF Research Database (Denmark)

    Molin, Sebastian; Chen, Ming; Bowen, Jacob R.

    2013-01-01

    this relatively short time all the metallic nickel in the coating has reacted and formed solid solutions with iron and chromium. Diffusion of Ni into the steel causes formation of the austenite FCC phase. The microstructure and composition of the oxide scale formed on the sample surface after 250 hours is similar......Stainless steels are used as interconnects in Solid Oxide Fuel Cell/Electrolysis stacks. Their high temperature corrosion resistance has been studied mainly to describe oxide scale formation processes. Other corrosion/degradation processes may also be of relevance to overall life time, for example...... diffusion of nickel from the Ni/YSZ electrode or the contact layer into the interconnect plate. Such diffusion can cause austenization of the ferritic structure and could possibly alter corrosion properties of the steel. Whereas this process has already been recognized by SOFC stack developers, only...

  8. Quality Assurance of Solid Oxide Fuel Cell (SOFC) and Electrolyser (SOEC) Stacks

    DEFF Research Database (Denmark)

    Lang, Michael; Auer, Corinna; Couturier, Karine

    2017-01-01

    In the EU-funded project “Solid oxide cell and stack testing and quality assurance” (SOCTESQA) standardized and industry wide test modules and programs for high temperature solid oxide cells and stacks are being developed. These test procedures can be applied for the fuel cell (SOFC......, electrochemical impedance spectroscopy, reactant utilization, reactant gas composition, temperature sensitivity, operation at constant current, operation at varying current, thermal cycling and shut-down. The test modules were validated by comparing the results in terms of repeatability of the different testing......), the electrolysis (SOEC) and in the combined SOFC/SOEC mode. In order to optimize the test modules the project partners have tested identical SOC stacks with the same test programs in several testing campaigns. Altogether 10 pre-normative test modules were developed: Start-up, current-voltage characteristics...

  9. Carbon source and energy harvesting optimization in solid anolyte microbial fuel cells

    Science.gov (United States)

    Adekunle, Ademola; Raghavan, Vijaya; Tartakovsky, Boris

    2017-07-01

    This work investigates the application of a solid anolyte microbial fuel cell (saMFC) as a long-lasting source of electricity for powering electronic devices. Broadly available biodegradable materials such as humus, cattle manure, peat moss, and sawdust are evaluated as solid anolytes. The initial comparison shows significantly higher power production in the saMFC operated using humus as compared to other solid anolytes. At the same time, power production in the humus-based saMFC is found to decline after about 40 days of operation, while the sawdust MFC demonstrates stable performance over the test period. Following this initial comparison, a combined humus - sawdust anolyte is developed to increase saMFC life span. The optimized saMFC demonstrates stable power production for over nine months. Furthermore, power production in the saMFC is maximized by using an intermittent connection to an electrical load (on/off operation) and optimizing the connection/disconnection times. These results demonstrate the feasibility of utilizing solid anolytes for developing inexpensive and long-lasting biobatteries operated on renewable carbon sources.

  10. Reversible solid oxide fuel cells (R-SOFCs) with chemically stable proton-conducting oxides

    KAUST Repository

    Bi, Lei

    2015-07-01

    Proton-conducting oxides offer a promising way of lowering the working temperature of solid oxide cells to the intermediate temperate range (500 to 700. °C) due to their better ionic conductivity. In addition, the application of proton-conducting oxides in both solid oxide fuel cells (SOFCs) and sold oxide electrolysis cells (SOECs) provides unique advantages compared with the use of conventional oxygen-ion conducting conductors, including the formation of water at the air electrode site. Since the discovery of proton conduction in some oxides about 30. years ago, the development of proton-conducting oxides in SOFCs and SOECs (the reverse mode of SOFCs) has gained increased attention. This paper briefly summarizes the development in the recent years of R-SOFCs with proton-conducting electrolytes, focusing on discussing the importance of adopting chemically stable materials in both fuel cell and electrolysis modes. The development of electrode materials for proton-conducting R-SOFCs is also discussed. © 2015 Elsevier B.V.

  11. Biogas Catalytic Reforming Studies on Nickel-Based Solid Oxide Fuel Cell Anodes

    DEFF Research Database (Denmark)

    Johnson, Gregory B.; Hjalmarsson, Per; Norrman, Kion

    2016-01-01

    Heterogeneous catalysis studies were conducted on two crushed solid oxide fuel cell (SOFC) anodes in fixed-bed reactors. The baseline anode was Ni/ScYSZ (Ni/scandia and yttria stabilized zirconia), the other was Ni/ScYSZ modified with Pd/doped ceria (Ni/ScYSZ/Pd-CGO). Three main types of experime......Heterogeneous catalysis studies were conducted on two crushed solid oxide fuel cell (SOFC) anodes in fixed-bed reactors. The baseline anode was Ni/ScYSZ (Ni/scandia and yttria stabilized zirconia), the other was Ni/ScYSZ modified with Pd/doped ceria (Ni/ScYSZ/Pd-CGO). Three main types......-programmed oxidation and time-of-flight secondary ion mass spectrometry. Results showed thatNi/ScYSZ/Pd-CGO was more active for catalytic dissociation of CH4 at 750°C and subsequent reactivity of deposited carbonaceous species. Sulfur deactivated most catalytic reactions except CO2 dissociation at 750°C. The presence...

  12. Interactions of nickel/zirconia solid oxide fuel cell anodes with coal gas containing arsenic

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, Christopher A.; Marina, Olga A.; Thomsen, Edwin C.; Edwards, Danny J.; Cramer, Carolyn N.; Coffey, Greg W.; Pederson, Larry R.

    2009-04-01

    The performance of anode-supported and electrolyte-supported solid oxide fuel cells was investigated in synthetic coal gas containing 0 to 10 ppm arsenic introduced as arsine. Arsenic was found to interact strongly with nickel in the anode, resulting in the formation of nickel-arsenic solid solution, Ni5As2 and Ni11As8, depending on temperature, arsenic concentration, and reaction time. For anode-supported cells, loss of electrical connectivity in the anode support was the principal mode of degradation, as nickel was converted to nickel arsenide phases that migrated to the surface to form large grains. Cell failure occurred well before the entire anode was converted to nickel arsenide, and followed a reciprocal square root of arsenic partial pressure dependence consistent with a diffusion-based rate-limiting step. Failure occurred more quickly with electrolyte-supported cells, which have a substantially smaller nickel inventory. For these cells, time to failure varied linearly with the reciprocal arsenic concentration in coal gas, and occurred when arsenic reached the anode/electrolyte interface. Test performed with nickel/zirconia coupons showed that arsenic was essentially completely captured in a narrow band near the fuel gas inlet.

  13. Characterization of proton exchange membrane materials for fuel cells by solid state nuclear magnetic resonance

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Zueqian [Iowa State Univ., Ames, IA (United States)

    2010-01-01

    Solid-state nuclear magnetic resonance (NMR) has been used to explore the nanometer-scale structure of Nafion, the widely used fuel cell membrane, and its composites. We have shown that solid-state NMR can characterize chemical structure and composition, domain size and morphology, internuclear distances, molecular dynamics, etc. The newly-developed water channel model of Nafion has been confirmed, and important characteristic length-scales established. Nafion-based organic and inorganic composites with special properties have also been characterized and their structures elucidated. The morphology of Nafion varies with hydration level, and is reflected in the changes in surface-to-volume (S/V) ratio of the polymer obtained by small-angle X-ray scattering (SAXS). The S/V ratios of different Nafion models have been evaluated numerically. It has been found that only the water channel model gives the measured S/V ratios in the normal hydration range of a working fuel cell, while dispersed water molecules and polymer ribbons account for the structures at low and high hydration levels, respectively.

  14. Reversible solid oxide fuel cell for natural gas/renewable hybrid power generation systems

    Science.gov (United States)

    Luo, Yu; Shi, Yixiang; Zheng, Yi; Cai, Ningsheng

    2017-02-01

    Renewable energy (RE) is expected to be the major part of the future energy. Presently, the intermittence and fluctuation of RE lead to the limitation of its penetration. Reversible solid oxide fuel cell (RSOFC) as the energy storage device can effectively store the renewable energy and build a bidirectional connection with natural gas (NG). In this paper, the energy storage strategy was designed to improve the RE penetration and dynamic operation stability in a distributed system coupling wind generators, internal combustion engine, RSOFC and lithium-ion batteries. By compromising the relative deviation of power supply and demand, RE penetration, system efficiency and capacity requirement, the strategy that no more than 36% of the maximum wind power output is directly supplied to users and the other is stored by the combination of battery and reversible solid oxide fuel cell is optimal for the distributed system. In the case, the RE penetration reached 56.9% and the system efficiency reached 55.2%. The maximum relative deviation of power supply and demand is also lower than 4%, which is significantly superior to that in the wind curtailment case.

  15. Kinetic Studies on State of the Art Solid Oxide Cells – A Comparison between Hydrogen/Steam and Reformate Fuels

    DEFF Research Database (Denmark)

    Njodzefon, Jean-Claude; Graves, Christopher R.; Mogensen, Mogens Bjerg

    2015-01-01

    /steam and reformate fuels hydrogen/carbon-dioxide and hydrogen/methane/steam. It was found that the kinetics at the fuel electrode were exactly the same in both reformates. The hydrogen/steam fuel displayed slightly faster kinetics than the reformate fuels. Furthermore the gas conversion impedance in the hydrogen...... into a single process as the gas conversion was reduced. The SOC with finer electrode microstructure displayed improved kinetics.......Electrochemical reaction kinetics at the electrodes of Solid Oxide Cells (SOCs) were investigated at 700 °C for two cells with different fuel electrode microstructures as well as on a third cell with a reduced active electrode area. Three fuel mixtures were investigated – hydrogen...

  16. Design of a thermally integrated bioethanol-fueled solid oxide fuel cell system integrated with a distillation column

    Science.gov (United States)

    Jamsak, W.; Douglas, P. L.; Croiset, E.; Suwanwarangkul, R.; Laosiripojana, N.; Charojrochkul, S.; Assabumrungrat, S.

    Solid oxide fuel cell systems integrated with a distillation column (SOFC-DIS) have been investigated in this study. The MER (maximum energy recovery) network for SOFC-DIS system under the base conditions (C EtOH = 25%, EtOH recovery = 80%, V = 0.7 V, fuel utilization = 80%, T SOFC = 1200 K) yields Q Cmin = 73.4 and Q Hmin = 0 kW. To enhance the performance of SOFC-DIS, utilization of internal useful heat sources from within the system (e.g. condenser duty and hot water from the bottom of the distillation column) and a cathode recirculation have been considered in this study. The utilization of condenser duty for preheating the incoming bioethanol and cathode recirculation for SOFC-DIS system were chosen and implemented to the SOFC-DIS (CondBio-CathRec). Different MER designs were investigated. The obtained MER network of CondBio-CathRec configuration shows the lower minimum cold utility (Q Cmin) of 55.9 kW and total cost index than that of the base case. A heat exchanger loop and utility path were also investigated. It was found that eliminate the high temperature distillate heat exchanger can lower the total cost index. The recommended network is that the hot effluent gas is heat exchanged with the anode heat exchanger, the external reformer, the air heat exchanger, the distillate heat exchanger and the reboiler, respectively. The corresponding performances of this design are 40.8%, 54.3%, 0.221 W cm -2 for overall electrical efficiency, Combine Heat and Power (CHP) efficiency and power density, respectively. The effect of operating conditions on composite curves on the design of heat exchanger network was investigated. The obtained composite curves can be divided into two groups: the threshold case and the pinch case. It was found that the pinch case which T SOFC = 1173 K yields higher total cost index than the CondBio-CathRec at the base conditions. It was also found that the pinch case can become a threshold case by adjusting split fraction or operating at

  17. Design of a thermally integrated bioethanol-fueled solid oxide fuel cell system integrated with a distillation column

    Energy Technology Data Exchange (ETDEWEB)

    Jamsak, W.; Assabumrungrat, S. [Center of Excellence in Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University (Thailand); Douglas, P.L.; Croiset, E. [Department of Chemical Engineering, University of Waterloo (Canada); Suwanwarangkul, R. [School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasart University-Rangsit Campus, Patum Thani 12121 (Thailand); Laosiripojana, N. [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology, Thonburi (Thailand); Charojrochkul, S. [National Metal and Materials Technology Center (MTEC) (Thailand)

    2009-02-01

    Solid oxide fuel cell systems integrated with a distillation column (SOFC-DIS) have been investigated in this study. The MER (maximum energy recovery) network for SOFC-DIS system under the base conditions (C{sub EtOH} = 25%, EtOH recovery = 80%, V = 0.7 V, fuel utilization = 80%, T{sub SOFC} = 1200 K) yields Q{sub Cmin} = 73.4 and Q{sub Hmin} = 0 kW. To enhance the performance of SOFC-DIS, utilization of internal useful heat sources from within the system (e.g. condenser duty and hot water from the bottom of the distillation column) and a cathode recirculation have been considered in this study. The utilization of condenser duty for preheating the incoming bioethanol and cathode recirculation for SOFC-DIS system were chosen and implemented to the SOFC-DIS (CondBio-CathRec). Different MER designs were investigated. The obtained MER network of CondBio-CathRec configuration shows the lower minimum cold utility (Q{sub Cmin}) of 55.9 kW and total cost index than that of the base case. A heat exchanger loop and utility path were also investigated. It was found that eliminate the high temperature distillate heat exchanger can lower the total cost index. The recommended network is that the hot effluent gas is heat exchanged with the anode heat exchanger, the external reformer, the air heat exchanger, the distillate heat exchanger and the reboiler, respectively. The corresponding performances of this design are 40.8%, 54.3%, 0.221 W cm{sup -2} for overall electrical efficiency, Combine Heat and Power (CHP) efficiency and power density, respectively. The effect of operating conditions on composite curves on the design of heat exchanger network was investigated. The obtained composite curves can be divided into two groups: the threshold case and the pinch case. It was found that the pinch case which T{sub SOFC} = 1173 K yields higher total cost index than the CondBio-CathRec at the base conditions. It was also found that the pinch case can become a threshold case by adjusting

  18. Improvement in retention of solid fission products in HTGR fuel particles by ceramic kernel additives

    Energy Technology Data Exchange (ETDEWEB)

    Foerthmann, R.; Groos, E.; Gruebmeier, H.

    1975-08-15

    Increased requirements concerning the retention of long-lived solid fission products in fuel elements for use in advanced High Temperature Gas-cooled Reactors led to the development of coated particles with improved fission product retention which represent an alternative to silicon carbide-coated fuel particles. Two irradiation experiments have shown that the release of strontium, barium, and caesium from pyrocarbon-coated particles can be reduced by orders of magnitude if the oxide kernel contains alumina-silica additives. It was detected by electron microprobe analysis that the improved retention of the mentioned fission products in the fuel kernel is caused by formation of the stable aluminosilicates SrAl2Si2O8, BaAl2Si2O8and CsAlSi2O6 in the additional alumina-silica phase of the kernel.

  19. Development of planar solid oxide fuel cells for power generation applications

    Energy Technology Data Exchange (ETDEWEB)

    Minh, N.Q. [AlliedSignal Aerospce Equipment Systems, Torrance, CA (United States)

    1996-04-01

    Planar solid oxide fuel cells (SOFCs) are presently being developed for a variety of electric power generation application. The planar design offers simple cell geometry, high power density, and multiple fabrication and gas manifolding options. Planar SOFC technology has received much attention recently, and significant progress has been made in this area. Recent effort at AlliedSignal has focused on the development of high-performance, lightweight planar SOFCs, having thin-electrolyte films, that can be operated efficiently at reduced temperatures (< 1000{degrees}C). The advantages of reduced-temperature operation include wider material choice (including use of metallic interconnects), expected longer cell life, reduced thermal stress, improved reliability, and reduced fuel cell cost. The key aspect in the development of thin-film SIFCs is to incorporate the thin electrolyte layer into the desired structure of cells in a manner that yields the required characteristics. AlliedSignal has developed a simple and cost-effective method based on tape calendering for the fabrication of thin-electrolyte SOFCs. Thin-electrolyte cells made by tape calendering have shown extraordinary performance, e.g., producing more than 500mW/cm{sup 2} at 700{degrees}C and 800mW/cm{sup 2} at 800{degrees}C with hydrogen as fuel and air is oxidant. thin-electrolyte single cells have been incorporated into a compliant metallic stack structure and operated at reduced and operated at reduced-temperature conditions.

  20. An all-in-one flourite-based symmetrical solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Morales, Juan Carlos; Marrero-Lopez, David; Perez-Coll, Domingo; Pena-Martinez, Juan; Nunez, Pedro [Department of Inorganic Chemistry, University of La Laguna, Avda. Francisco Sanchez s/n, La Laguna, CP 38200 Tenerife (Spain); Canales-Vazquez, Jesus [Renewable Energy Research Institute, University of Castilla la Mancha, 02006 Albacete (Spain)

    2008-02-15

    A novel concept of solid oxide fuel cell (SOFC), the symmetrical SOFC, that uses simultaneously the same material as both anode and cathode has been investigated. Common materials typically used as anode components such as a combination of YSZ and CeO{sub 2} plus a noble metal may be considered good candidates for such a configuration at relatively high temperatures (i.e. above 900 C). These symmetrical electrodes exhibit enhanced electrochemical properties under both reducing and oxidising conditions, in part due to the catalytic properties of the noble metal used. In air the polarisation values are improved by a factor of four compared to electrodes without CeO{sub 2}, whereas under reducing conditions an improvement of two-three orders of magnitude has been observed. The best results correspond to cermets containing 50-60% of CeO{sub 2}. This simple combination allows the assembly of all-in-one fluorite-based symmetrical fuel cells (SFCs): YSZ-CeO{sub 2}/YSZ/YSZ-CeO{sub 2} plus a noble metal with good catalytic behaviour. Performances of 140 mW cm{sup -2} at 950 C were obtained when using H{sub 2} as fuel and thick YSZ electrolytes. Interesting performances of 500 mW cm{sup -2} are expected for thin YSZ electrolyte layer under identical experimental conditions. (author)

  1. Is the biochar produced from sewage sludge a good quality solid fuel?

    Directory of Open Access Journals (Sweden)

    Pulka Jakub

    2016-12-01

    Full Text Available The influence of sewage sludge torrefaction temperature on fuel properties was investigated. Non-lignocellulosic waste thermal treatment experiment was conducted within 1 h residence time, under the following temperatures: 200, 220, 240, 260, 280 and 300°C. Sawdust was used as lignocellulosic reference material. The following parameters of biochar have been measured: moisture, higher heating value, ash content, volatile compounds and sulfur content. Sawdust biochar has been confirmed to be a good quality solid fuel. High ash and sulfur content may be an obstacle for biochar energy reuse. The best temperature profile for sawdust torrefaction and fuel production for 1 h residence time was 220°C. At this temperature the product contained 84% of initial energy while decreased the mass by 25%. The best temperature profile for sewage sludge was 240°C. The energy residue was 91% and the mass residue was 85%. Higher temperatures in both cases caused excessive mass and energy losses.

  2. Cfd Analysis of Heat Transfer in a Microtubular Solid Oxide Fuel Cell Stack

    Directory of Open Access Journals (Sweden)

    Pianko-Oprych Paulina

    2014-09-01

    Full Text Available The aim of this work was to achieve a deeper understanding of the heat transfer in a microtubular Solid Oxide Fuel Cell (mSOFC stack based on the results obtained by means of a Computational Fluid Dynamics tool. Stack performance predictions were based on simulations for a 16 anodesupported mSOFCs sub-stack, which was a component of the overall stack containing 64 fuel cells. The emphasis of the paper was put on steady-state modelling, which enabled identification of heat transfer between the fuel cells and air flow cooling the stack and estimation of the influence of stack heat losses. Analysis of processes for different heat losses and the impact of the mSOFC reaction heat flux profile on the temperature distribution in the mSOFC stack were carried out. Both radiative and convective heat transfer were taken into account in the analysis. Two different levels of the inlet air velocity and three different values of the heat losses were considered. Good agreement of the CFD model results with experimental data allowed to predict the operation trends, which will be a reliable tool for optimisation of the working setup and ensure sufficient cooling of the mSOFC stack.

  3. A high performance cathode for proton conducting solid oxide fuel cells

    KAUST Repository

    Wang, Zhiquan

    2015-01-01

    Intermediate temperature solid-oxide fuel cells (IT-SOFCs)), as one of the energy conversion devices, have attracted worldwide interest for their great fuel efficiency, low air pollution, much reduced cost and excellent longtime stability. In the intermediate temperature range (500-700°C), SOFCs based on proton conducting electrolytes (PSOFCs) display unique advantages over those based on oxygen ion conducting electrolytes. A key obstacle to the practical operation of past P-SOFCs is the poor stability of the traditionally used composite cathode materials in the steam-containing atmosphere and their low contribution to proton conduction. Here we report the identification of a new Ruddlesden-Popper-type oxide Sr3Fe2O7-δ that meets the requirements for much improved long-term stability and shows a superior single-cell performance. With a Sr3Fe2O7-δ-5 wt% BaZr0.3Ce0.5Y0.2O3-δ cathode, the P-SOFC exhibits high power densities (683 and 583 mW cm-2 at 700°C and 650°C, respectively) when operated with humidified hydrogen as the fuel and air as the cathode gas. More importantly, no decay in discharging was observed within a 100 hour test. © The Royal Society of Chemistry 2015.

  4. Improvement in the solid-state alkaline fuel cell performance through efficient water management strategies

    Science.gov (United States)

    Oshiba, Yuhei; Hiura, Junya; Suzuki, Yuto; Yamaguchi, Takeo

    2017-03-01

    In solid-state alkaline fuel cells (SAFCs), water is generated at the anode and is reacted at the cathode; as such, flooding occurs much more easily at the anode than it does in proton-exchange membrane fuel cells (PEMFCs). Anode flooding is a reason for the low performance of SAFCs, and so it is important that this flooding phenomenon is mitigated. In this study, we control water transport to suppress anode flooding. We do this through two approaches: changing the thickness of the anion exchange membrane (AEM) and changing the anode flow rate. Among two AEMs with two different thicknesses (27 μm and 6 μm) prepared, thinner AEM shows improved fuel cell performance. Increasing the anode flow rate also improved the performance of SAFCs. To find out what caused this, the water transport inside the membrane electrode assembly (MEA) was analyzed. The flooding region was estimated using calculated relative humidity at anode outlet. On the basis of our experimental and calculation approaches, flooding can be suppressed by using thin AEMs and increasing the anode flow rate.

  5. Mechanism for carbon direct electrochemical reactions in a solid oxide electrolyte direct carbon fuel cell

    Science.gov (United States)

    Li, Chen; Shi, Yixiang; Cai, Ningsheng

    The carbon direct electrochemical reactions in a solid oxide electrolyte direct carbon fuel cell (DCFC) are investigated experimentally with CH 4-deposited carbon at the anode as fuel. The surface morphology of the anode cross-sections is characterized using a scanning electron microscope (SEM), the elemental distribution using an energy dispersive spectrometer (EDS) and an X-ray photoelectron spectroscopy (XPS), and the deposited carbon microstructures using a Raman spectrometer. The results indicate that all the carbon deposited on the yttrium-stabilized zirconium (YSZ) particle surfaces, the Ni particle surfaces, as well as the three-phase boundary, can participate in the electrochemical reactions during the fuel cell discharging. The direct electrochemical reactions for carbon require the two conditions that the O 2- in the ionic conductor contact with a carbon reactive site and that the released electrons are conducted to the external circuit. The electrochemical reactions for the deposited carbon are most difficult on the Ni particle surfaces, easier on the YSZ particle surfaces and easiest at the three-phase boundary. Not all the carbon deposited in the anode participates in the direct electrochemical reactions. The deposited carbon and the O 2- in the YSZ react to form the double-bonded adsorbed carbonyl group C dbnd O.

  6. Thermal Cyclability of Reactive Air Braze Seals in Anode Supported Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Hardy, John S.; Darsell, Jens T.; Coyle, Christopher A.; Birnbaum, Jerome C.; Weil, K. Scott

    2004-12-31

    The popularity of anode-supported solid oxide fuel cells (SOFC) has increased in tandem with the ability to fabricate thinner gas-tight yttrium-stabilized zirconia (YSZ) electrolyte layers, which can now be routinely produced on the order of 7 to 10 μm thick. While this has significantly improved power output and decreased the required fuel cell operating temperatures, the ability to reliably seal fuel cells remains a concern. The seals must be hermetic and be robust enough to retain their hermeticity even under the extreme operating conditions of SOFCs. Perhaps the largest contributor to stresses experienced by the seal is the fact that the SOFC is an assembly of many different materials with different thermal expansion properties. Although every effort is made to minimize thermal expansion mismatches across the seals, the stresses developed during thermal cycling still jeopardize seal integrity. Reactive air brazing (RAB), a method of joining that employs a metallic, and therefore non-brittle, seal material has been used to seal electrolyte/anode bilayers, such as those in anode-supported SOFCs, to Crofer-22 alloy. The results of rupture strength testing will be reported for as-brazed and thermally cycled samples and the effect of thermal cycling on the RAB seal microstructure will be shown

  7. Dynamic modeling and evaluation of solid oxide fuel cell - combined heat and power system operating strategies

    Science.gov (United States)

    Nanaeda, Kimihiro; Mueller, Fabian; Brouwer, Jacob; Samuelsen, Scott

    Operating strategies of solid oxide fuel cell (SOFC) combined heat and power (CHP) systems are developed and evaluated from a utility, and end-user perspective using a fully integrated SOFC-CHP system dynamic model that resolves the physical states, thermal integration and overall efficiency of the system. The model can be modified for any SOFC-CHP system, but the present analysis is applied to a hotel in southern California based on measured electric and heating loads. Analysis indicates that combined heat and power systems can be operated to benefit both the end-users and the utility, providing more efficient electric generation as well as grid ancillary services, namely dispatchable urban power. Design and operating strategies considered in the paper include optimal sizing of the fuel cell, thermal energy storage to dispatch heat, and operating the fuel cell to provide flexible grid power. Analysis results indicate that with a 13.1% average increase in price-of-electricity (POE), the system can provide the grid with a 50% operating range of dispatchable urban power at an overall thermal efficiency of 80%. This grid-support operating mode increases the operational flexibility of the SOFC-CHP system, which may make the technology an important utility asset for accommodating the increased penetration of intermittent renewable power.

  8. Investigations into the interactions between sulfur and anodes for solid oxide fuel cells

    Science.gov (United States)

    Cheng, Zhe

    Solid oxide fuel cells (SOFCs) are electrochemical devices based on solid oxide electrolytes that convert chemical energy in fuels directly into electricity via electrode reactions. SOFCs have the advantages of high energy efficiency and low emissions and hold the potential to be the power of the future especially for small power generation systems (1-10 kW). Another unique advantage of SOFCs is the potential to directly utilize hydrocarbon fuels such as natural gas through internal reforming. However, all hydrocarbon fuels contain some sulfur compounds, which transform to hydrogen sulfide (H2S) in the reforming process and dramatically degrade the performance of the existing SOFCs. In this study, the interactions between sulfur contaminant (in the form of H2S) and the anodes for SOFCs were systematically investigated in order to gain a fundamental understanding of the mechanism of sulfur poisoning and ultimately to achieve rational design of sulfur-tolerant anodes. The sulfur poisoning behavior of the state-of-the-art Ni-YSZ cermet anodes was characterized using electrochemical measurements performed on button cells (of different structures) under various operating conditions, including H2S concentration, temperature, cell current density/terminal voltage, and cell structure. Also, the mechanisms of interactions between sulfur and the Ni-YSZ cermet anode were investigated using both ex situ and in situ characterization techniques such as Raman spectroscopy. Results suggest that the sulfur poisoning of Ni-YSZ cermet anodes at high temperatures in fuels with ppm-level H2S is due not to the formation of multi-layer conventional nickel sulfides but to the adsorption of sulfur on the nickel surface. In addition, new sulfur-tolerant anode materials were explored in this study. Thermodynamic principles were applied to predict the stability of candidate sulfur-tolerant anode materials and explain complex phenomena concerning the reactivity of candidate materials with

  9. Study on Zinc Oxide-Based Electrolytes in Low-Temperature Solid Oxide Fuel Cells.

    Science.gov (United States)

    Xia, Chen; Qiao, Zheng; Feng, Chu; Kim, Jung-Sik; Wang, Baoyuan; Zhu, Bin

    2017-12-28

    Semiconducting-ionic conductors have been recently described as excellent electrolyte membranes for low-temperature operation solid oxide fuel cells (LT-SOFCs). In the present work, two new functional materials based on zinc oxide (ZnO)-a legacy material in semiconductors but exceptionally novel to solid state ionics-are developed as membranes in SOFCs for the first time. The proposed ZnO and ZnO-LCP (La/Pr doped CeO₂) electrolytes are respectively sandwiched between two Ni 0.8 Co 0.15 Al 0.05 Li-oxide (NCAL) electrodes to construct fuel cell devices. The assembled ZnO fuel cell demonstrates encouraging power outputs of 158-482 mW cm -2 and high open circuit voltages (OCVs) of 1-1.06 V at 450-550 °C, while the ZnO-LCP cell delivers significantly enhanced performance with maximum power density of 864 mW cm -2 and OCV of 1.07 V at 550 °C. The conductive properties of the materials are investigated. As a consequence, the ZnO electrolyte and ZnO-LCP composite exhibit extraordinary ionic conductivities of 0.09 and 0.156 S cm -1 at 550 °C, respectively, and the proton conductive behavior of ZnO is verified. Furthermore, performance enhancement of the ZnO-LCP cell is studied by electrochemical impedance spectroscopy (EIS), which is found to be as a result of the significantly reduced grain boundary and electrode polarization resistances. These findings indicate that ZnO is a highly promising alternative semiconducting-ionic membrane to replace the electrolyte materials for advanced LT-SOFCs, which in turn provides a new strategic pathway for the future development of electrolytes.

  10. A solid oxide fuel cell with a gadolinia-doped ceria anode: Preparation and performance

    DEFF Research Database (Denmark)

    Marina, O.A.; Bagger, C.; Primdahl, S.

    1999-01-01

    The application of doped ceria as an anode material in high-temperature solid oxide fuel cells (SOFC) is described. Deposition of an anchoring layer of YSZ particles was used to obtain sufficient adhesion between a porous Ce0.6Gd0.4O1.8 (CG4) anode and an yrttria-stabilised zirconia (YSZ) electro......The application of doped ceria as an anode material in high-temperature solid oxide fuel cells (SOFC) is described. Deposition of an anchoring layer of YSZ particles was used to obtain sufficient adhesion between a porous Ce0.6Gd0.4O1.8 (CG4) anode and an yrttria-stabilised zirconia (YSZ......) electrolyte without detrimental reaction. Single SOFCs comprising the CG4 anode, a composite strontium-doped lanthanum manganite-based cathode and the YSZ electrolyte were manufactured and tested in H-2/H2O and CH4/H2O atmospheres vs. air in the temperature range of 800-1015 degrees C, An area specific...... internal resistance of 0.39 Ohm cm(2) at 0.71 V cell voltage and a power density of 470 mW/cm(2) was obtained at 1000 degrees C using H-2/H2O/N-2 = 9/1.2/89.8 as the fuel and air as oxidant. A current density of 0.25 A/cm(2) at an area specific internal resistance of 2 Ohm cm(2) was obtained with CH4/H2O...

  11. Program of scientific investigations and development of solid-oxide fuel cells (SOFC) in VIITF proposals on scientific and technical collaboration and SOFC commercialization

    Energy Technology Data Exchange (ETDEWEB)

    Kleschev, Yu.N.; Chulharev, V.F.

    1996-04-01

    Investigations being performed at VNIITF covers the whole cycle of solid oxide fuel cell manufacturing. This report describes the main directions of investigations in materials, technologies, and commercialization.

  12. Experimental and numerical investigation on the ignition and combustion stability in solid fuel ramjet with swirling flow

    Science.gov (United States)

    Musa, Omer; Xiong, Chen; Changsheng, Zhou

    2017-08-01

    The present article investigates experimentally and numerically the ignition and flame stability of high-density polyethylene solid fuel with incoming swirling air through a solid fuel ramjet (SFRJ). A new design of swirler is proposed and used in this work. Experiments on connected pipes test facility were performed for SFRJ with and without swirl. An in-house code has been developed to simulate unsteady, turbulent, reacting, swirling flow in the SFRJ. Four different swirl intensities are utilized to study experimentally and numerically the effect of swirl number on the transient regression, ignition of the solid fuel in a hot-oxidizing flow and combustion phenomenon in the SFRJ. The results showed that using swirl flow decreases the ignition time delay, recirculation zone length, and the distance between the flame and the wall, meanwhile, increases the residence time, heat transfer, regression rate and mixing degree, thus, improving the combustion efficiency and stability.

  13. Electrical Generation for More-Electric Aircraft Using Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Whyatt, Greg A.; Chick, Lawrence A.

    2012-04-01

    This report examines the potential for Solid-Oxide Fuel Cells (SOFC) to provide electrical generation on-board commercial aircraft. Unlike a turbine-based auxiliary power unit (APU) a solid oxide fuel cell power unit (SOFCPU) would be more efficient than using the main engine generators to generate electricity and would operate continuously during flight. The focus of this study is on more-electric aircraft which minimize bleed air extraction from the engines and instead use electrical power obtained from generators driven by the main engines to satisfy all major loads. The increased electrical generation increases the potential fuel savings obtainable through more efficient electrical generation using a SOFCPU. However, the weight added to the aircraft by the SOFCPU impacts the main engine fuel consumption which reduces the potential fuel savings. To investigate these relationships the Boeing 787­8 was used as a case study. The potential performance of the SOFCPU was determined by coupling flowsheet modeling using ChemCAD software with a stack performance algorithm. For a given stack operating condition (cell voltage, anode utilization, stack pressure, target cell exit temperature), ChemCAD software was used to determine the cathode air rate to provide stack thermal balance, the heat exchanger duties, the gross power output for a given fuel rate, the parasitic power for the anode recycle blower and net power obtained from (or required by) the compressor/expander. The SOFC is based on the Gen4 Delphi planar SOFC with assumed modifications to tailor it to this application. The size of the stack needed to satisfy the specified condition was assessed using an empirically-based algorithm. The algorithm predicts stack power density based on the pressure, inlet temperature, cell voltage and anode and cathode inlet flows and compositions. The algorithm was developed by enhancing a model for a well-established material set operating at atmospheric pressure to reflect the

  14. Effect of binder burnout on the sealing performance of glass ceramics for solid oxide fuel cells

    Science.gov (United States)

    Ertugrul, Tugrul Y.; Celik, Selahattin; Mat, Mahmut D.

    2013-11-01

    The glass ceramics composite sealants are among few materials suitable for the solid oxide fuel cells (SOFC) due to their high operating temperatures (600 °C-850 °C). The glass ceramics chemically bond to both the metallic interconnector and the ceramic electrolyte and provide a gas tight connection. A careful and several stages manufacturing procedure is required to obtain a gas tight sealing. In this study, effects of binder burnout process on the sealing performance are investigated employing commercially available glass ceramic powders. The glass ceramic laminates are produced by mixing glass ceramic powders with the organic binders and employing a tape casting method. The laminates are sandwiched between the metallic interconnectors of an SOFC cell. The burnout and subsequent sealing quality are analyzed by measuring leakage rate and final macrostructure of sealing region. The effects of heating rate, dead weight load, solid loading, carrier gas and their flow rates are investigated. It is found that sealing quality is affected from all investigated parameters. While a slower heating rate is required for a better burnout, the mass flow rate of sweep gas must be adequate for removal of the burned gas. The leakage rate is reduced to 0.1 ml min-1 with 2 °C min-1 + 1 °C min-1 heating rate, 86.25% solid loading, 200 N dead weight load and 500 ml min-1 sweep gas flow rate.

  15. Mathematical modeling of synthesis gas fueled electrochemistry and transport including H2/CO co-oxidation and surface diffusion in solid oxide fuel cell

    Science.gov (United States)

    Bao, Cheng; Jiang, Zeyi; Zhang, Xinxin

    2015-10-01

    Fuel flexibility is a significant advantage of solid oxide fuel cell (SOFC). A comprehensive macroscopic framework is proposed for synthesis gas (syngas) fueled electrochemistry and transport in SOFC anode with two main novelties, i.e. analytical H2/CO electrochemical co-oxidation, and correction of gas species concentration at triple phase boundary considering competitive absorption and surface diffusion. Staring from analytical approximation of the decoupled charge and mass transfer, we present analytical solutions of two defined variables, i.e. hydrogen current fraction and enhancement factor. Giving explicit answer (rather than case-by-case numerical calculation) on how many percent of the current output contributed by H2 or CO and on how great the water gas shift reaction plays role on, this approach establishes at the first time an adaptive superposition mechanism of H2-fuel and CO-fuel electrochemistry for syngas fuel. Based on the diffusion equivalent circuit model, assuming series-connected resistances of surface diffusion and bulk diffusion, the model predicts well at high fuel utilization by keeping fixed porosity/tortuosity ratio. The model has been validated by experimental polarization behaviors in a wide range of operation on a button cell for H2-H2O-CO-CO2-N2 fuel systems. The framework could be helpful to narrow the gap between macro-scale and meso-scale SOFC modeling.

  16. Use of wastewater treatment plant biogas for the operation of Solid Oxide Fuel Cells (SOFCs).

    Science.gov (United States)

    Lackey, Jillian; Champagne, Pascale; Peppley, Brant

    2017-12-01

    Solid Oxide Fuel Cells (SOFCs) perform well on light hydrocarbon fuels, and the use of biogas derived from the anaerobic digestion (AD) of municipal wastewater sludges could provide an opportunity for the CH 4 produced to be used as a renewable fuel. Greenhouse gas (GHG), NO x , SO x , and hydrocarbon pollutant emissions would also be reduced. In this study, SOFCs were operated on AD derived biogas. Initially, different H 2 dilutions were tested (N 2 , Ar, CO 2 ) to examine the performance of tubular SOFCs. With inert gases as diluents, a decrease in cell performance was observed, however, the use of CO 2 led to a higher decrease in performance as it promoted the reverse water-gas shift (WGS) reaction, reducing the H 2 partial pressure in the gas mixture. A model was developed to predict system efficiency and GHG emissions. A higher electrical system efficiency was noted for a steam:carbon ratio of 2 compared to 1 due to the increased H 2 partial pressure in the reformate resulting from higher H 2 O concentration. Reductions in GHG emissions were estimated at 2400 tonnes CO 2 , 60 kg CH 4 and 18 kg N 2 O. SOFCs were also tested using a simulated biogas reformate mixture (66.7% H 2 , 16.1% CO, 16.5% CO 2 , 0.7% N 2 , humidified to 2.3 or 20 mol% H 2 O). Higher humidification yielded better performance as the WGS reaction produced more H 2 with additional H 2 O. It was concluded that AD-derived biogas, when cleaned to remove H 2 S, Si compounds, halides and other contaminants, could be reformed to provide a clean, renewable fuel for SOFCs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Thermodynamic assessment of solid oxide fuel cell system integrated with bioethanol purification unit

    Energy Technology Data Exchange (ETDEWEB)

    Jamsak, W.; Assabumrungrat, S. [Center of Excellence in Catalysis and Catalytic Reaction Engineering, Department of Chemical Engineering, Faculty of Engineering, Chulalongkorn University (Thailand); Douglas, P.L.; Croiset, E. [Department of Chemical Engineering, University of Waterloo (Canada); Laosiripojana, N. [The Joint Graduate School of Energy and Environment, King Mongkut' s University of Technology, Thonburi (Thailand); Suwanwarangkul, R. [School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasart University, Rangsit Campus, Patum Thani 12121 (Thailand); Charojrochkul, S. [National Metal and Materials Technology Center (MTEC) (Thailand)

    2007-11-22

    A solid oxide fuel cell system integrated with a distillation column (SOFC-DIS) has been proposed in this article. The integrated SOFC system consists of a distillation column, an EtOH/H{sub 2}O heater, an air heater, an anode preheater, a reformer, an SOFC stack and an afterburner. Bioethanol with 5 mol% ethanol was purified in a distillation column to obtain a desired concentration necessary for SOFC operation. The SOFC stack was operated under isothermal conditions. The heat generated from the stack and the afterburner was supplied to the reformer and three heaters. The net remaining heat from the SOFC system (Q{sub SOFC,Net}) was then provided to the reboiler of the distillation column. The effects of fuel utilization and operating voltage on the net energy (Q{sub Net}), which equals Q{sub SOFC,Net} minus the distillation energy (Q{sub D}), were examined. It was found that the system could become more energy sufficient when operating at lower fuel utilization or lower voltage but at the expense of less electricity produced. Moreover, it was found that there were some operating conditions, which yielded Q{sub Net} of zero. At this point, the integrated system provides the maximum electrical power without requiring an additional heat source. The effects of ethanol concentration and ethanol recovery on the electrical performance at zero Q{sub Net} for different fuel utilizations were investigated. With the appropriate operating conditions (e.g. C{sub EtOH} = 41%, U{sub f} = 80% and EtOH recovery = 80%), the overall electrical efficiency and power density are 33.3% (LHV) and 0.32 W cm{sup -2}, respectively. (author)

  18. Emissions from residential combustion of different solid fuels. Roekgasemissioner vid anvaendning av olika fasta braenslen i smaaskaliga system

    Energy Technology Data Exchange (ETDEWEB)

    Rudling, L.

    1983-01-01

    The emission from different types of solid fuels during combustion in residential furnaces and stoves has been investigated. The following fules were investigated: wood pellets, peat-bark pellets, wood chips, wood logs,wood-briquets, peat briquets, lignite briquets, fuel oil. Three different 20-25 kW boilers were used and one stove and one fire place. The flue gases were analysed for carbon dioxide, carbon monoxide, nitrogen oxides, hydrocarbons, particulates, tar and fluoranthen.

  19. Phase 1 - Evaluation of a Functional Interconnect System for Solid Oxide Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    James M. Rakowski

    2006-09-30

    This project is focused on evaluating the suitability of materials and complex multi-materials systems for use as solid oxide fuel cell interconnects. ATI Allegheny Ludlum has generated promising results for interconnect materials which incorporate modified surfaces. Methods for producing these surfaces include cladding, which permits the use of novel materials, and modifications via unique thermomechanical processing, which allows for the modification of materials chemistry. The University of Pittsburgh is assisting in this effort by providing use of their in-place facilities for dual atmosphere testing and ASR measurements, along with substantial work to characterize post-exposure specimens. Carnegie Mellon is testing interconnects for chromia scale spallation resistance using macro-scale and nano-scale indentation tests. Chromia spallation can increase electrical resistance to unacceptable levels and interconnect systems must be developed that will not experience spallation within 40,000 hours at operating temperatures. Spallation is one of three interconnect failure mechanisms, the others being excessive growth of the chromia scale (increasing electrical resistance) and scale evaporation (which can poison the cathode). The goal of indentation fracture testing at Carnegie Mellon is to accelerate the evaluation of new interconnect systems (by inducing spalls at after short exposure times) and to use fracture mechanics to understand mechanisms leading to premature interconnect failure by spallation. Tests include bare alloys from ATI and coated systems from DOE Laboratories and industrial partners, using ATI alloy substrates. West Virginia University is working towards developing a cost-effective material for use as a contact material in the cathode chamber of the SOFC. Currently materials such as platinum are well suited for this purpose, but are cost-prohibitive. For the solid-oxide fuel cell to become a commercial reality it is imperative that lower cost

  20. Methane-free biogas for direct feeding of solid oxide fuel cells

    Science.gov (United States)

    Leone, P.; Lanzini, A.; Santarelli, M.; Calì, M.; Sagnelli, F.; Boulanger, A.; Scaletta, A.; Zitella, P.

    This paper deals with the experimental analysis of the performance and degradation issues of a Ni-based anode-supported solid oxide fuel cell fed by a methane-free biogas from dark-anaerobic digestion of wastes by pastry and fruit shops. The biogas is produced by means of an innovative process where the biomass is fermented with a pre-treated bacteria inoculum (Clostridia) able to completely inhibit the methanization step during the fermentation process and to produce a H 2/CO 2 mixture instead of conventional CH 4/CO 2 anaerobic digested gas (bio-methane). The proposed biogas production route leads to a biogas composition which avoids the need of introducing a reformer agent into or before the SOFC anode in order to reformate it. In order to analyse the complete behaviour of a SOFC with the bio-hydrogen fuel, an experimental session with several H 2/CO 2 synthetic mixtures was performed on an anode-supported solid oxide fuel cell with a Ni-based anode. It was found that side reactions occur with such mixtures in the typical thermodynamic conditions of SOFCs (650-800 °C), which have an effect especially at high currents, due to the shift to a mixture consisting of hydrogen, carbon monoxide, carbon dioxide and water. However, cells operated with acceptable performance and carbon deposits (typical of a traditional hydrocarbon-containing biogas) were avoided after 50 h of cell operation even at 650 °C. Experiments were also performed with traditional bio-methane from anaerobic digestion with 60/40 vol% of composition. It was found that the cell performance dropped after few hours of operation due to the formation of carbon deposits. A short-term test with the real as-produced biogas was also successfully performed. The cell showed an acceptable power output (at 800 °C, 0.35 W cm -2 with biogas, versus 0.55 W cm -2 with H 2) although a huge quantity of sulphur was present in the feeding fuel (hydrogen sulphide at 103 ppm and mercaptans up to 10 ppm). Therefore, it

  1. Indoor air pollution from solid biomass fuels combustion in rural agricultural area of Tibet, China.

    Science.gov (United States)

    Gao, X; Yu, Q; Gu, Q; Chen, Y; Ding, K; Zhu, J; Chen, L

    2009-06-01

    In this study, we are trying to investigate the indoor air pollution and to estimate the residents' pollution exposure reduction of energy altering in rural Tibet. Daily PM(2.5) monitoring was conducted in indoor microenvironments like kitchen, living-room, bedroom, and yard in rural Tibet from December 2006 to March 2007. For kitchen air pollution, impact of two fuel types, methane and solid biomass fuels (SBFs), were compared. Questionnaire survey on the domestic energy pattern and residents' daily activity pattern was performed in Zha-nang County. Daily average PM(2.5) concentrations in kitchen, living-room, bedroom, and yard were 134.91 microg/m(3) (mean, n = 45, 95%CI 84.02, 185.80), 103.61 microg/m(3) (mean, n = 21, 95%CI 85.77, 121.45), 76.13 microg/m(3) (mean, n = 18, 95%CI 57.22, 95.04), and 78.33 microg/m(3) (mean, n = 34, 95%CI 60.00, 96.65) respectively. Using SBFs in kitchen resulted in higher indoor pollution than using methane. PM(2.5) concentrations in kitchen with dung cake, fuel wood and methane use were 117.41 microg/m(3) (mean, n = 18, 95%CI 71.03, 163.79), 271.11 microg/m(3) (mean, n = 12, 95%CI 104.74, 437.48), and 46.96 microg/m(3) (mean, n = 15, 95%CI 28.10, 65.82) respectively. Family income has significant influence on cooking energy choice, while the lack of commercial energy supply affects the energy choice for heating more. The effects of two countermeasures to improve indoor air quality were estimated in this research. One is to replace SBFs by clean energy like methane, the other is to separate the cooking place from other rooms and by applying these countermeasures, residents' exposure to particulate matters would reduce by 25-50% (methane) or 20-30% (separation) compared to the present situation. Indoor air pollution caused by solid biomass fuels is one of the most important burdens of disease in the developing countries, which attracts the attention of environment and public health researchers, as well as policy makers. This paper

  2. Methane-free biogas for direct feeding of solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Leone, P.; Lanzini, A.; Santarelli, M.; Cali, M. [Dipartimento di Energetica, Politecnico di Torino, Corso Duca degli Abruzzi 24, 10129 Turin (Italy); Sagnelli, F.; Boulanger, A.; Scaletta, A.; Zitella, P. [BioEnergy Lab, Environment Park S.p.A., Via Livorno 60, 10144 Turin (Italy)

    2010-01-01

    This paper deals with the experimental analysis of the performance and degradation issues of a Ni-based anode-supported solid oxide fuel cell fed by a methane-free biogas from dark-anaerobic digestion of wastes by pastry and fruit shops. The biogas is produced by means of an innovative process where the biomass is fermented with a pre-treated bacteria inoculum (Clostridia) able to completely inhibit the methanization step during the fermentation process and to produce a H{sub 2}/CO{sub 2} mixture instead of conventional CH{sub 4}/CO{sub 2} anaerobic digested gas (bio-methane). The proposed biogas production route leads to a biogas composition which avoids the need of introducing a reformer agent into or before the SOFC anode in order to reformate it. In order to analyse the complete behaviour of a SOFC with the bio-hydrogen fuel, an experimental session with several H{sub 2}/CO{sub 2} synthetic mixtures was performed on an anode-supported solid oxide fuel cell with a Ni-based anode. It was found that side reactions occur with such mixtures in the typical thermodynamic conditions of SOFCs (650-800 C), which have an effect especially at high currents, due to the shift to a mixture consisting of hydrogen, carbon monoxide, carbon dioxide and water. However, cells operated with acceptable performance and carbon deposits (typical of a traditional hydrocarbon-containing biogas) were avoided after 50 h of cell operation even at 650 C. Experiments were also performed with traditional bio-methane from anaerobic digestion with 60/40 vol% of composition. It was found that the cell performance dropped after few hours of operation due to the formation of carbon deposits. A short-term test with the real as-produced biogas was also successfully performed. The cell showed an acceptable power output (at 800 C, 0.35 W cm{sup -2} with biogas, versus 0.55 W cm{sup -2} with H{sub 2}) although a huge quantity of sulphur was present in the feeding fuel (hydrogen sulphide at 103 ppm and

  3. Interaction of coal-derived synthesis gas impurities with solid oxide fuel cell metallic components

    Energy Technology Data Exchange (ETDEWEB)

    Marina, Olga A.; Coyle, Christopher A.; Edwards, Danny J.; Chou, Yeong-Shyung; Cramer, Carolyn N. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Pederson, Larry R. [North Dakota State University, Fargo, ND 58102 (United States)

    2011-01-15

    Oxidation-resistant alloys find use as interconnect materials, heat exchangers, and gas supply tubing in solid oxide fuel cell (SOFC) systems, especially when operated at temperatures below {proportional_to}800 C. If fueled with synthesis gas derived from coal or biomass, such metallic components could be exposed to impurities contained in those fuel sources. In this study, coupons of ferritic stainless steels Crofer 22 APU and SS 441, austenitic nickel-chromium superalloy Inconel 600, and an alumina-forming high nickel alloy alumel were exposed to synthesis gas containing {<=}2 ppm phosphorus, arsenic and antimony, and reaction products were tested. Crofer 22 APU coupons coated with a (Mn,Co){sub 3}O{sub 4} protective layer were also evaluated. Phosphorus was found to be the most reactive. On Crofer 22 APU, the (Mn,Cr){sub 3}O{sub 4} passivation layer reacted to form an Mn-P-O product, predicted to be manganese phosphate from thermochemical calculations, and Cr{sub 2}O{sub 3}. On SS 441, reaction of phosphorus with (Mn,Cr){sub 3}O{sub 4} led to the formation of manganese phosphate as well as an Fe-P product, predicted from thermochemical calculations to be Fe{sub 3}P. Minimal interactions with antimony or arsenic in synthesis gas were limited to Fe-Sb and Fe-As solid solution formation. Though not intended for use on the anode side, a (Mn,Co){sub 3}O{sub 4} spinel coating on Crofer 22 APU reacted with phosphorus in synthesis gas to produce products consistent with Mn{sub 3}(PO{sub 4}){sub 2} and Co{sub 2}P. A thin Cr{sub 2}O{sub 3} passivation layer on Inconel 600 did not prevent the formation of nickel phosphides and arsenides and of iron phosphides and arsenides, though no reaction with Cr{sub 2}O{sub 3} was apparent. On alumel, an Al{sub 2}O{sub 3} passivation layer rich in Ni did not prevent the formation of nickel phosphides, arsenides, and antimonides, though no reaction with Al{sub 2}O{sub 3} occurred. This work shows that unprotected metallic components of

  4. A feasibility study of hydrothermal treatment of rice straw for multi-production of solid fuel and liquid fertilizer

    Science.gov (United States)

    Samnang, S.; Prawisudha, P.; Pasek, A. D.

    2017-05-01

    Energy use has increased steadily over the last century due to population and industry increase. With the growing of GHG, biomass becomes an essential contributor to the world energy need. Indonesia is the third rice producer in the world. Rice straw has been converted to solid fuel by Hydrothermal Treatment (HT) for electricity generation. HT is a boiling solid organic or inorganic substance in water at high pressure and temperature within a holding time. HT converts high moisture content biomass into dried, uniform, pulverized, and higher energy density solid fuels. HT can effectively transport nutrient components in biomass into a liquid product known as fertilizer. This paper deals with an evaluation of hydrothermal treatment of rice straw for solid fuel and liquid fertilizer. An investigation of rice straw characteristics were completed for Bandung rice straw with various condition of temperature, biomass-water ratio, and holding time in the purpose to find the changes of calorific value for solid product and (N, P, K, and pH) for liquid product. The results showed that solid product at 225 °C and 90 min consists in a heating value 13.8 MJ/kg equal to lignite B. Liquid product at 225 °C and 90 min had the NPK content similar to that of micronutrients compound liquid fertilizer. The dried solid product should be useful for Coal Fire Power Plant, and the liquid product is suitable for plants. This research proves that hydrothermal process can be applied to rice straw to produce solid fuel and liquid fertilizer with adequate quality.

  5. Reversible Operation of Solid Oxide Cells for Sustainable Fuel Production and Solar/Wind Load-Balancing

    DEFF Research Database (Denmark)

    Graves, Christopher R.; Villarreal, D.; Mýrdal, Jón Steinar Garðarsson

    2016-01-01

    electricity from fuels – either previously stored fuels or from anexternal supply e.g. natural gas or biogas. This reversibility combined with fuel-flexibility isunique among energy storage technologies like closed-system batteries and singledirectionelectrolyzers. However, few studies have been conducted......RSOC stack produces syngas via co-electrolysis of CO2 and H2O. Part of the syngas isconverted to methanol downstream in the system to meet the demand of transportationvehicles, and the rest is stored for electrical load balancing by conversion back toelectricity in fuel cell mode when electricity demand......The solid oxide electrochemical cell (SOC) is a promising candidate for large-scale energystorage. In electrolysis mode it stores renewable electricity as chemical energy in the formof fuels like hydrogen and hydrocarbons, and the same cell can be operated in the reversedirection to produce...

  6. Fracture toughness of glass sealants for solid oxide fuel cell application

    DEFF Research Database (Denmark)

    Abdoli, Hamid; Alizadeh, Parvin; Boccaccini, Dino

    2014-01-01

    Glass and glass-ceramics are versatile materials and have been widely used for sealing in the ongoing development of intermediate temperature solid oxide fuel cell (SOFC) technology where its integrity is crucial for reliable operation of the stack. The fracture toughness is a key parameter...... required for the prediction of the mechanical performance of a seal glass. A comparative indentation study on two RE-glasses (RE=La and Y) was performed to evaluate their fracture toughness. Indentation toughness was calculated both through measurements of the indentation crack lengths and of crack......-opening displacements in the near regions of a crack tip. Both approaches exhibited good agreement. La-containing glass showed higher stiffness, hardness and fracture toughness, which has been related to the in-situ toughening mechanism caused by devitrification and formation of crystalline phases. © 2013 Elsevier B.V....

  7. Performance of a novel type of electrolyte-supported solid oxide fuel cell with honeycomb structure

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Morales, Juan Carlos; Savvin, Stanislav N.; Nunez, Pedro [Departmento de Quimica Inorganica, Universidad de La Laguna, 38200 Tenerife (Spain); Marrero-Lopez, David [Departamento de Fisica Aplicada I, Universidad de Malaga, 29071 Malaga (Spain); Pena-Martinez, Juan; Canales-Vazquez, Jesus [Instituto de Energias Renovables-Universidad de Castilla la Mancha, 02006 Albacete (Spain); Roa, Joan Josep; Segarra, Merce [DIOPMA, Departamento de Ciencia de los Materiales e Ing. Metalurgica, 08028 Barcelona (Spain)

    2010-01-15

    A novel design, alternative to the conventional electrolyte-supported solid oxide fuel cell (SOFC) is presented. In this new design, a honeycomb-electrolyte is fabricated from hexagonal cells, providing high mechanical strength to the whole structure and supporting the thin layer used as electrolyte of a SOFC. This new design allows a reduction of {proportional_to}70% of the electrolyte material and it renders modest performances over 320 mW cm{sup -2} but high volumetric power densities, i.e. 1.22 W cm{sup -3} under pure CH{sub 4} at 900 C, with a high OCV of 1.13 V, using the standard Ni-YSZ cermet as anode, Pt as cathode material and air as the oxidant gas. (author)

  8. Solid oxide fuel cells powered by biomass gasification for high efficiency power generation

    DEFF Research Database (Denmark)

    Gadsbøll, Rasmus Østergaard; Thomsen, Jesper; Bang-Møller, Christian

    2017-01-01

    Increased use of bioenergy is a very cost-effective and flexible measure to limit changes in the climate and the infrastructure. One of the key technologies toward a higher implementation of biomass is thermal gasification, which enables a wide span of downstream applications. In order to improve...... efficiencies, flexibility and possibly costs of current biomass power generating systems, a power plant concept combining solid oxide fuel cells (SOFC) and gasification is investigated experimentally. The aim of the study is to examine the commercial operation system potential of these two technologies...... part-load operation; and a longer test to investigate stability. The study shows experimentally the potential and feasibility of a SOFC-gasification system with a commercial gasifier and a SOFC stack by measuring the highest reported values of such a system, with biomass-to-electricity efficiencies up...

  9. Energy recuperation in solid oxide fuel cell (SOFC) and gas turbine (GT) combined system

    Science.gov (United States)

    Kuchonthara, Prapan; Bhattacharya, Sankar; Tsutsumi, Atsushi

    A combined power generation system consisting of a solid oxide fuel cell (SOFC) and a gas turbine (GT) with steam and heat recuperation (HR) was evaluated using a commercial process simulation tool, ASPEN Plus. The effect of steam recuperation (SR) on the overall efficiency of the combined system was investigated by comparing the SOFC-GT during heat and steam recuperation (HSR) against the system during only heat recuperation. At low turbine inlet temperatures (TITs), the overall efficiency of the SOFC-GT combined system with heat and steam recuperation improved by showing an increase in TIT and a reduction in pressure ratio (PR). On the other hand, at high TITs, the opposite trend was observed. The integration of steam recuperation was found to improve the overall efficiency and specific power of SOFC-GT combined systems with a relatively compact SOFC component.

  10. Hydrothermal Upgrading of Korean MSW for Solid Fuel Production: Effect of MSW Composition

    Directory of Open Access Journals (Sweden)

    Daegi Kim

    2012-01-01

    In this research, the hydrothermal treatment was applied to treat the surrogate MT residue composed of paper and/or kimchi. It was shown that the hydrothermal treatment increased the calorific value of the surrogate MT residue due to increasing fixed carbon content and decreasing oxygen content and enhanced the dehydration and drying performances of kimchi. Comparing the results of paper and kimchi samples, the calorific value of the treated product from paper was increased more effectively due to its high content of cellulose. Furthermore, the change of the calorific value before and after the hydrothermal treatment of the mixture of paper and kimchi can be well predicted by this change of paper and kimchi only. The hydrothermal treatment can be expected to effectively convert high moisture MT residue into a uniform solid fuel.

  11. Optimization of the stand for test of hybrid rocket engines of solid fuel

    Directory of Open Access Journals (Sweden)

    Zolotorev Nikolay

    2017-01-01

    Full Text Available In the paper the laboratory experimental stand of the hybrid rocket engine of solid fuel to study ballistic parameters of the engine at burning of high-energy materials in flow of hot gas is presented. Mixture of air with nitrogen with a specified content of active oxygen is used as a gaseous oxidizer. The experimental stand has modular design and consists of system of gas supply, system of heating of gas, system for monitoring gas parameters, to which a load cell with a model engine was connected. The modular design of the stand allows to change its configuration under specific objective. This experimental stand allows to conduct a wide range of the pilot studies at interaction of a hot stream of gas with samples high-energy materials.

  12. Electrochemically active thickness of solid oxide fuel cell electrodes: Effectiveness model prediction

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Jin Hyun [School of Mechanical Engineering, Daegu University, Gyungsan (Korea, Republic of)

    2017-04-15

    The three-phase boundaries (TPBs) in the electrodes of solid oxide fuel cells (SOFCs) have different activity because of the distributed nature of the electrochemical reactions. The electrochemically active thickness (EAT) is a good measure to evaluate the extension of the active reaction zone into the electrode and the effective utilization of TPBs. In this study, an electrochemical reaction/charge conduction problem is formulated based on the Butler–Volmer reaction kinetics and then numerically solved to determine the EATs for the active electrode layers of SOFCs with various microstructural, dimensional, and property parameters. Thus, the EAT data and correlations presented in this study are expected to provide useful information for designing efficient electrodes of SOFCs.

  13. Microstructure-scaled active sites imaging of a solid oxide fuel cell composite cathode

    Science.gov (United States)

    Nagasawa, Tsuyoshi; Hanamura, Katsunori

    2017-11-01

    Active sites for oxygen reduction reaction in strontium-doped lanthanum manganite (LSM)/scandia-stabilized zirconia (ScSZ) composite cathode of solid oxide fuel cell (SOFC) is visualized in microstructure scale by oxygen isotope labeling. In order to quench a reaction, a SOFC power generation equipment with a nozzle for direct helium gas impinging jet to the cell is prepared. A typical electrolyte-supported cell is operated by supplying 18O2 at 1073 K and abruptly quenched to room temperature. During the quench, the temperature of the cell is decreased from 1073 K to 673 K in 1 s. The 18O concentration distribution in the cross section of the quenched cathode is obtained by secondary ion mass spectrometry (SIMS) with a spatial resolution of 50 nm. The obtained 18O mapping gives the first visualization of highly distributed active sites in the composite cathode both in macroscopic and particle scales.

  14. Nanostructured Gd-CeO2 electrolyte for solid oxide fuel cell by aqueous tape casting

    Science.gov (United States)

    Akbari-Fakhrabadi, A.; Mangalaraja, R. V.; Sanhueza, Felipe A.; Avila, Ricardo E.; Ananthakumar, S.; Chan, S. H.

    2012-11-01

    Gadolinia-doped ceria (Ce0.9Gd0.1O1.95, GDC) electrolyte was fabricated by aqueous-based tape casting method for solid oxide fuel cells (SOFCs). The ceramic powder prepared by combustion synthesis was used with poly acrylic acid (PAA), poly vinyl alcohol (PVA), poly ethylene glycol (PEG), Octanol, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylate and double distilled water as dispersant, binder, plasticizer, defoamer, surfactant and solvent respectively, to prepare stable GDC slurry. The conditions for preparing stable GDC slurries were studied and optimized by sedimentation, zeta potential and viscosity measurements. Green tapes with smooth surface, flexibility, thickness in the range of 0.35-0.4 mm and 45% relative green density were prepared. Conventional and flash sintering techniques were used and compared for densification which demonstrated the possibility of surpassing sintering at high temperatures and retarding related grain growth.

  15. Elaboration and characterisation of functionally graded cathodes for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Simonet, J.; Kapelski, G.; Bouvard, D. [Laboratoire de Genie Physique et Mecanique des Materiaux, Institut National Polytechnique de Grenoble, CNRS UMR 5010, BP 46, 38042 Saint Martin d' Heres cedex (France)

    2005-07-01

    The industrial development of solid oxide fuel cells (SOFC) requires decreasing their operating temperature from 1000 deg. C to 700 deg. C while keeping acceptable mechanical and electrochemical performances. A solution consists in designing composite bulk cathodes with numerous electro-chemical reaction sites. The fabrication of such cathodes has been investigated with classical materials as lanthanum strontium manganese (LSM) and yttrium stabilized zirconia (YSZ), which is also the constitutive material of the electrolyte. A composite cathode with continuous composition gradient has been obtained by co-sedimentation of the powders in a liquid and subsequent firing. The obtained composition is investigated with Scanning Electron Microscope (SEM) and Electron Dispersive Spectrometry (EDS). It is found to be in good agreement with the prediction of a numerical model of the sedimentation process. (authors)

  16. Life cycle sustainability of solid oxide fuel cells: From methodological aspects to system implications

    Science.gov (United States)

    Mehmeti, Andi; McPhail, Stephen J.; Pumiglia, Davide; Carlini, Maurizio

    2016-09-01

    This study reviews the status of life cycle assessment (LCA) of Solid Oxide Fuel Cells (SOFCs) and methodological aspects, communicates SOFC environmental performance, and compares the environmental performance with competing power production technologies using a life cycle perspective. Results indicate that power generation using SOFCs can make a significant contribution to the aspired-to greener energy future. Despite superior environmental performance, empirical studies indicate that economic performance is predominantly the highest-ranked criterion in the decision making process. Future LCA studies should attempt to employ comprehensive dynamic multi-criteria environmental impact analysis coupled with economic aspects, to allow a robust comparison of results. A methodology framework is proposed to achieve simultaneously ambitious socio-economic and environmental objectives considering all life cycle stages and their impacts.

  17. Indirect Determination of Chemical Composition and Fuel Characteristics of Solid Waste

    DEFF Research Database (Denmark)

    Riber, Christian; Christensen, Thomas Højlund

    Determination of chemical composition of solid waste can be performed directly or indirectly by analysis of combustion products. The indirect methodology instrumented by a full scale incinerator is the only method that can conclude on elements in trace concentrations. These elements are of great...... interest in evaluating waste management options by for example LCA modeling. A methodology description of indirect determination of chemical composition and fuel properties of waste is provided and validated by examples. Indirect analysis of different waste types shows that the chemical composition...... is significantly dependent on waste type. And the analysis concludes that the transfer of substances in the incinerator is a function of waste chemical content, incinerator technology and waste physical properties. The importance of correct representation of rare items in the waste with high concentrations...

  18. Secondary creep of porous metal supports for solid oxide fuel cells by a CDM approach

    DEFF Research Database (Denmark)

    Esposito, L.; Boccaccini, D. N.; Pucillo, G. P.

    2017-01-01

    The creep behaviour of porous iron-chromium alloy used in solid oxide fuel cells (SOFCs) becomes relevant under SOFC operating temperatures. In this paper, the secondary creep stage of infiltrated and non-infiltrated porous metal supports (MS) was investigated and theoretically modelled...... as function of temperature, determined by the high temperature impulse excitation technique, was directly used to account for the porosity and the related effective stress acting during the creep tests. The proposed creep rate formulation was used to extend the Crofer® 22 APU Monkman-Grant diagram...... by a continuum damage mechanics (CDM) approach. The behaviour of the porous metal support, in the range from 1 to 17MPa and temperatures between 650 and 700°C, was combined and compared with data from literature of Crofer® 22 APU, taken as zero porosity reference material. The variation of the elastic modulus...

  19. High performance metal-supported solid oxide fuel cells with Gd-doped ceria barrier layers

    DEFF Research Database (Denmark)

    Klemensø, Trine; Nielsen, Jimmi; Blennow Tullmar, Peter

    2011-01-01

    Metal-supported solid oxide fuel cells are believed to have commercial advantages compared to conventional anode (Ni–YSZ) supported cells, with the metal-supported cells having lower material costs, increased tolerance to mechanical and thermal stresses, and lower operational temperatures......, and an electrochemical performance beyond the state-of-the-art anode-supported SOFC is demonstrated possible, by introducing a CGO barrier layer in combination with Sr-doped lanthanum cobalt oxide (LSC) cathode. Area specific resistances (ASR) down to 0.27 Ω cm2, corresponding to a maximum power density of 1.14 W cm−2...... at 650 °C and 0.6 V, were obtained on cells with barrier layers fabricated by magnetron sputtering. The performance is dependent on the density of the barrier layer, indicating Sr2+ diffusion is occurring at the intermediate SOFC temperatures. The optimized design further demonstrate improved durability...

  20. Alternative fuel production by catalytic hydroliquefaction of solid municipal wastes, primary sludges and microalgae.

    Science.gov (United States)

    Lemoine, F; Maupin, I; Lemée, L; Lavoie, J-M; Lemberton, J-L; Pouilloux, Y; Pinard, L

    2013-08-01

    An alternative fuel production was investigated through catalytic hydroliquefaction of three different carbonaceous sources: solid municipal wastes (MW), primary sludges (PS), and microalgae (MA). The reaction was carried out under hydrogen pressure, at different temperatures (330, 380 and 450°C), with a Raney nickel catalyst and two different hydrogen donor solvents: a "fossil solvent" (tetralin) and a "green solvent" (2-methyl-hydro-furan). The feeds analyses (TDA-TGA, ICP-AES, lipids quantification) showed that MW and PS had similar characteristics and physico-chemical properties, but different from those of MA. The hydroliquefaction of these feeds allowed to obtain high oil yields, with a significant energetic value, similar to that of a bio-petroleum. 2-methyl-hydro-furan was more efficient than tetralin for the treatment of the strongly bio-degraded biomasses MW and PS, while better results were obtained with tetralin in the case of MA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Nanofiber-based composite cathodes for intermediate temperature solid oxide fuel cells

    Science.gov (United States)

    Ahn, Minwoo; Lee, Jongseo; Lee, Wonyoung

    2017-06-01

    We demonstrate the Sm0.5Sr0.5CoO3-δ (SSC) nanofiber-based composite cathodes for intermediate temperature solid oxide fuel cells (IT-SOFCs), showing a cathode area-specific resistance (ASR) value of 0.024 Ωcm2 at 650 °C. The hollow and porous SSC nanofiber layer, fabricated by electrospinning, is sintered at low temperatures to preserve the high specific surface area for facile oxygen surface exchange reactions. The low sintering temperature is enabled by additional SSC powder layer, providing sufficient adhesion between the electrolyte and the nanofiber layer. Our results can provide a design guideline to fully utilize the nanostructured electrodes by engineering the structural properties of the surface and the interface, and hence high-performance IT-SOFCs can be achieved by structural modification with conventional materials.

  2. Design and development of major balance of plant components in solid oxide fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Wen-Tang; Huang, Cheng-Nan; Tan, Hsueh-I; Chao, Yu [Institute of Nuclear Energy Research Atomic Energy Council, Taoyuan County 32546 (Taiwan, Province of China); Yen, Tzu-Hsiang [Green Technology Research Institute, CPC Corporation, Chia-Yi City 60036 (Taiwan, Province of China)

    2013-07-01

    The balance of plant (BOP) of a Solid Oxide Fuel Cell (SOFC) system with a 2 kW stack and an electric efficiency of 40% is optimized using commercial GCTool software. The simulation results provide a detailed understanding of the optimal operating temperature, pressure and mass flow rate in all of the major BOP components, i.e., the gas distributor, the afterburner, the reformer and the heat exchanger. A series of experimental trials are performed to validate the simulation results. Overall, the results presented in this study not only indicate an appropriate set of operating conditions for the SOFC power system, but also suggest potential design improvements for several of the BOP components.

  3. Electrode materials: a challenge for the exploitation of protonic solid oxide fuel cells

    Directory of Open Access Journals (Sweden)

    Emiliana Fabbri, Daniele Pergolesi and Enrico Traversa

    2010-01-01

    Full Text Available High temperature proton conductor (HTPC oxides are attracting extensive attention as electrolyte materials alternative to oxygen-ion conductors for use in solid oxide fuel cells (SOFCs operating at intermediate temperatures (400–700 °C. The need to lower the operating temperature is dictated by cost reduction for SOFC pervasive use. The major stake for the deployment of this technology is the availability of electrodes able to limit polarization losses at the reduced operation temperature. This review aims to comprehensively describe the state-of-the-art anode and cathode materials that have so far been tested with HTPC oxide electrolytes, offering guidelines and possible strategies to speed up the development of protonic SOFCs.

  4. Cassettes for solid-oxide fuel cell stacks and methods of making the same

    Science.gov (United States)

    Weil, K. Scott; Meinhardt, Kerry D; Sprenkle, Vincent L

    2012-10-23

    Solid-oxide fuel cell (SOFC) stack assembly designs are consistently investigated to develop an assembly that provides optimal performance, and durability, within desired cost parameters. A new design includes a repeat unit having a SOFC cassette and being characterized by a three-component construct. The three components include an oxidation-resistant, metal window frame hermetically joined to an electrolyte layer of a multi-layer, anode-supported ceramic cell and a pre-cassette including a separator plate having a plurality of vias that provide electrical contact between an anode-side collector within the pre-cassette and a cathode-side current collector of an adjacent cell. The third component is a cathode-side seal, which includes a standoff that supports a cathode channel spacing between each of the cassettes in a stack. Cassettes are formed by joining the pre-cassette and the window frame.

  5. Testing and improving the redox stability of Ni-based solid oxide fuel cells

    DEFF Research Database (Denmark)

    Pihlatie, Mikko; Ramos, Tania; Kaiser, Andreas

    2009-01-01

    Despite active development, solid oxide fuel cells (SOFCs) based on Ni-YSZ anodes still suffer from thermomechanical instability under conditions where the anode side is exposed to oxidising conditions at high temperature. In the first part of the paper, structures and solutions, which could...... improve the redox stability of Ni-YSZ anode supported SOFC's in terms of dimensional and mechanical stability are reported. Porosity is identified as a major microstructural parameter linked to the dimensional and structural stability during redox cycling. The cumulative redox strain (CRS) after three...... isothermal redox cycles at 850 °C increases by a factor of more than 20 when the as-sintered porosity of the composites is reduced from 34 to 9%. The effect of reduction and redox cycling on the Ni-YSZ anode are discussed in light of electrochemical measurements using impedance spectroscopy on symmetric...

  6. Solid-state NMR and EPR Spectroscopy of Mn2+ -Substituted ATP-Fueled Protein Engines.

    Science.gov (United States)

    Wiegand, Thomas; Lacabanne, Denis; Keller, Katharina; Cadalbert, Riccardo; Lecoq, Lauriane; Yulikov, Maxim; Terradot, Laurent; Jeschke, Gunnar; Meier, Beat H; Böckmann, Anja

    2017-03-13

    Paramagnetic metal ions deliver structural information both in EPR and solid-state NMR experiments, offering a profitable synergetic approach to study bio-macromolecules. We demonstrate the spectral consequences of Mg2+ / Mn2+ substitution and the resulting information contents for two different ATP:Mg2+ -fueled protein engines, a DnaB helicase from Helicobacter pylori active in the bacterial replisome, and the ABC transporter BmrA, a bacterial efflux pump. We show that, while EPR spectra report on metal binding and provide information on the geometry of the metal centers in the proteins, paramagnetic relaxation enhancements identified in the NMR spectra can be used to localize residues at the binding site. Protein engines are ubiquitous and the methods described herein should be applicable in a broad context. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Ink-jet printing of electrolyte and anode functional layer for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Young, D.; Sukeshini, A.M.; Cummins, R. [Department of Mechanical and Materials Engineering, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45430 (United States); Xiao, H. [Aerospace Power and Propulsion, UES Corp., Dayton, OH 45432 (United States); Rottmayer, M.; Reitz, T. [The Air Force Research Laboratory, Propulsion Directorate, 1950 Fifth Street, Building 18, Wright-Patterson Air Force Base, OH 45433 (United States)

    2008-09-15

    In this work, solid oxide fuel cells were fabricated by ink-jet printing. The cells were characterized in order to study the resulting microstructure and electrochemical performance. Scanning electron microscopy revealed a highly conformal 6-12 {mu}m thick dense yttria-stabilized zirconia electrolyte layer, and a porous anode-interlayer. Open circuit voltages ranged from 0.95 to 1.06 V, and a maximum power density of 0.175 W cm{sup -2} was achieved at 750 C. These results suggest that the ink-jet printing technique may be used to fabricate stable SOFC structures that are comparable to those fabricated by more conventional ceramics processing methods. This study also highlights the significance of overall cell microstructural impact on cell performance and stability. (author)

  8. A global equilibrium analysis of co-firing coal and solid recovered fuel

    DEFF Research Database (Denmark)

    Wu, Hao; Glarborg, Peter; Jappe Frandsen, Flemming

    Global equilibrium calculations have been performed to study the behavior of ash forming species in cocombustion of a bituminous coal and a solid recovered fuel (SRF). It revealed that co-combustion of coal and 25% SRF (weight basis) could significantly reduce the formation of NaCl (g) and KCl (g...... to aluminosilicates during the flue gas cooling in the experiments, probably due to kinetic limitations. The results suggest that it is important to control the chlorine and alkali content in SRF, in order to facilitate co-combustion of coal and SRF....... method to increase the electrical efficiency of utilizing waste, as the aluminosilicates content in the coal could mitigate the ash related problems caused by the relative high chlorine and alkali content in the SRF. The influence of different SRF quality on the behavior of co-combustion was evaluated...

  9. Effect of Coal Gas Contaminants on Solid Oxide Fuel Cell Operation

    Energy Technology Data Exchange (ETDEWEB)

    Marina, Olga A.; Pederson, Larry R.; Edwards, Danny J.; Coyle, Christopher A.; Templeton, Jared W.; Engelhard, Mark H.; Zhu, Zihua

    2007-12-11

    The operation of solid oxide fuel cells (SOFC) was evaluated on simulated coal gas in the presence of several coal gas impurities that are expected to remain in low concentration after warm gas cleanup. Phosphorus, arsenic and sulfur were considered in this study. The presence of phosphorus and arsenic in low, 1-2 ppm, concentrations led to the slow and irreversible SOFC degradation due to the formation of the secondary phases with nickel in the upper part of the nickel-based anode close to the gas inlet. Sulfur interactions with the nickel were limited to the surface only. Cell performance losses due to sulfur exposure were reversible and independent of the presence of other impurities.

  10. Electrode assembly for use in a solid polymer electrolyte fuel cell

    Science.gov (United States)

    Raistrick, Ian D.

    1989-01-01

    A gas reaction fuel cell may be provided with a solid polymer electrolyte membrane. Porous gas diffusion electrodes are formed of carbon particles supporting a catalyst which is effective to enhance the gas reactions. The carbon particles define interstitial spaces exposing the catalyst on a large surface area of the carbon particles. A proton conducting material, such as a perfluorocarbon copolymer or ruthenium dioxide contacts the surface areas of the carbon particles adjacent the interstitial spaces. The proton conducting material enables protons produced by the gas reactions adjacent the supported catalyst to have a conductive path with the electrolyte membrane. The carbon particles provide a conductive path for electrons. A suitable electrode may be formed by dispersing a solution containing a proton conducting material over the surface of the electrode in a manner effective to coat carbon surfaces adjacent the interstitial spaces without impeding gas flow into the interstitial spaces.

  11. Solid oxide fuel cell power plant with an anode recycle loop turbocharger

    Science.gov (United States)

    Saito, Kazuo; Skiba, Tommy; Patel, Kirtikumar H.

    2015-07-14

    An anode exhaust recycle turbocharger (100) has a turbocharger turbine (102) secured in fluid communication with a compressed oxidant stream within an oxidant inlet line (218) downstream from a compressed oxidant supply (104), and the anode exhaust recycle turbocharger (100) also includes a turbocharger compressor (106) mechanically linked to the turbocharger turbine (102) and secured in fluid communication with a flow of anode exhaust passing through an anode exhaust recycle loop (238) of the solid oxide fuel cell power plant (200). All or a portion of compressed oxidant within an oxidant inlet line (218) drives the turbocharger turbine (102) to thereby compress the anode exhaust stream in the recycle loop (238). A high-temperature, automotive-type turbocharger (100) replaces a recycle loop blower-compressor (52).

  12. Optimization of spin-coated electrodes for electrolyte-supported solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Nobrega, Shayenne Diniz da; Monteiro, Natalia Kondo; Tabuti, Francisco; Fonseca, Fabio Coral, E-mail: shaynnedn@hotmail.com, E-mail: nataliakm@usp.br, E-mail: fntabuti@ipen.br, E-mail: fabiocf@usp.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN-CNEN/SP), Sao Paulo, SP (Brazil); Florio, Daniel Zanetti de, E-mail: daniel.florio@ufabc.edu.br [Universidade Federal do ABC (UFABC), Santo Andre, SP (Brazil)

    2017-01-15

    Electrodes for electrolyte-supported solid oxide fuel cells (SOFC’s) were fabricated by spin coating. Strontium-doped lanthanum manganite (LSM) cathode and nickel yttria-stabilized zirconia cermet anodes were synthesized and processed for enhanced deposition conditions. The influence of electrode microstructural parameters was investigated by a systematic experimental procedure aiming at optimized electrochemical performance of single cells. Polarization curves showed a strong dependence on both electrode thickness and sintering temperature. By a systematic control of such parameters, the performance of single cells was significantly enhanced due to decreasing of polarization resistance from 26 Ω cm² to 0.6 Ω cm² at 800°C. The results showed that spin-coated electrodes can be optimized for fast and cost effective fabrication of SOFCs. (author)

  13. Novel in situ method (vacuum assisted electroless plating) modified porous cathode for solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Su, Ren; Lue, Zhe; Chen, Kongfa; Ai, Na; Li, Shuyan; Wei, Bo [Center for the Condensed Matter Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Su, Wenhui [Center for the Condensed Matter Science and Technology, Harbin Institute of Technology, Harbin 150001 (China); Department of Condensed Matter Physics, Jilin University, Changchun 130023 (China); International Centre for Materials Physics, Academia Sinica, Shenyang 110015 (China)

    2008-06-15

    A novel in situ method - vacuum assisted electroless plating (VA-EP) is developed to modify the porous structure of various materials. The advantage of this method is that it can form a metal network based on the already-given structure. We utilize this method to deposit silver (VA-EPA) in porous perovskite cathode Ba{sub 0.5}Sr{sub 0.5}Co{sub 0.8}Fe{sub 0.2}O{sub 3-{delta}} (BSCF) for an intermediate temperature solid oxide fuel cell (IT-SOFC) in the present research. The results of investigation show the performance of the modified cathode (VA-EPA-BSCF) enhances greatly, for example, the polarization resistance of VA-EPA-BSCF decreases by 60% at 600 C compared to BSCF. (author)

  14. Methane Steam Reforming over an Ni-YSZ Solid Oxide Fuel Cell Anode in Stack Configuration

    Directory of Open Access Journals (Sweden)

    D. Mogensen

    2014-01-01

    Full Text Available The kinetics of catalytic steam reforming of methane over an Ni-YSZ anode of a solid oxide fuel cell (SOFC have been investigated with the cell placed in a stack configuration. In order to decrease the degree of conversion, a single cell stack with reduced area was used. Measurements were performed in the temperature range 600–800°C and the partial pressures of all reactants and products were varied. The obtained rates could be well fitted with a power law expression (r ∝PCH40.7. A simple model is presented which is capable of predicting the methane conversion in a stack configuration from intrinsic kinetics of the anode support material. The predictions are compared with the stack measurements presented here, and good agreement is observed.

  15. Thermodynamic Analysis of an Integrated Gasification Solid Oxide Fuel Cell Plant with a Kalina Cycle

    DEFF Research Database (Denmark)

    Pierobon, Leonardo; Rokni, Masoud

    2015-01-01

    A hybrid plant that consists of a gasification system, Solid Oxide Fuel Cells (SOFC) and a Simple Kalina Cycle (SKC) is investigated. Woodchips are introduced into a fixed bed gasification plant to produce syngas, which is then fed into an integrated SOFC-SKC plant to produce electricity. The pre...... system based on a gasification plant, a SOFC plant and a SKC plant is presented and investigated. The system is called IGSKC (Integrated Gasification SOFC Simple Kalina Cycle). The system layout is studied, and the optimal ammonia-water mole fraction is selected. An electrical efficiency of 58......% is achieved; plant size and nominal power are selected based on the required cultivation area. SOFC heat recovery with SKC is compared to a Steam Cycle (SC). Although ammonia-water more accurately fits the temperature profile of the off-gases, the presence of a Hybrid Recuperator enhances the available work...

  16. Effect of indoor air pollution from biomass and solid fuel combustion on symptoms of preeclampsia/eclampsia in Indian women.

    Science.gov (United States)

    Agrawal, S; Yamamoto, S

    2015-06-01

    Available evidence concerning the association between indoor air pollution (IAP) from biomass and solid fuel combustion and preeclampsia/eclampsia is not available in developing countries. We investigated the association between exposure to IAP from biomass and solid fuel combustion and symptoms of preeclampsia/eclampsia in Indian women by analyzing cross-sectional data from India's third National Family Health Survey (NFHS-3, 2005-2006). Self-reported symptoms of preeclampsia/eclampsia during pregnancy such as convulsions (not from fever), swelling of legs, body or face, excessive fatigue or vision difficulty during daylight, were obtained from 39,657 women aged 15-49 years who had a live birth in the previous 5 years. Effects of exposure to cooking smoke, ascertained by type of fuel used for cooking on preeclampsia/eclampsia risk, were estimated using logistic regression after adjusting for various confounders. Results indicate that women living in households using biomass and solid fuels have two times higher likelihood of reporting preeclampsia/eclampsia symptoms than do those living in households using cleaner fuels (OR = 2.21; 95%: 1.26-3.87; P = 0.006), even after controlling for the effects of a number of potentially confounding factors. This study is the first to empirically estimate the associations of IAP from biomass and solid fuel combustion and reported symptoms suggestive of preeclampsia/eclampsia in a large nationally representative sample of Indian women and we observed increased risk. These findings have important program and policy implications for countries such as India, where large proportions of the population rely on polluting biomass fuels for cooking and space heating. More epidemiological research with detailed exposure assessments and clinical measures of preeclampsia/eclampsia is needed in a developing country setting to validate these findings. © 2014 The Authors. Indoor Air published by John Wiley & Sons Ltd.

  17. Novel quasi-symmetric solid oxide fuel cells with enhanced electrochemical performance

    KAUST Repository

    Chen, Yonghong

    2016-02-16

    Symmetrical solid oxide fuel cell (SSOFC) using same materials as both anode and cathode simultaneously has gained extensively attentions, which can simplify fabrication process, minimize inter-diffusion between components, enhance sulfur and coking tolerance by operating the anode as the cathode in turn. With keeping the SSOFC\\'s advantages, a novel quasi-symmetrical solid oxide fuel cell (Q-SSOFC) is proposed to further improve the performance, which optimally combines two different SSOFC electrode materials as both anode and cathode simultaneously. PrBaFe2O5+δ (PBFO) and PrBaFe1.6Ni0.4O5+δ (PBFNO, Fe is partially substituted by Ni.) are prepared and applied as both cathode and anode for SSOFC, which exhibit desirable chemical and thermal compatibility with Sm0.8Ce0.2O1.9 (SDC) electrolyte. PBFO cathode exhibits higher oxygen reduction reaction (ORR) activity than PBFNO cathode in air, whereas PBFNO anode exhibits higher hydrogen oxidation reaction (HOR) activity than PBFO anode in H2. The as-designed Q-SSOFC of PBFNO/SDC/PBFO exhibits higher electrochemical performance than the conventional SSOFCs of both PBFO/SDC/PBFO and PBFNO/SDC/PBFNO. The superior performance of Q-SSOFC is attributed to the lowest polarization resistance (Rp). The newly developed Q-SSOFCs open doors for further improvement of electrochemical performance in SSOFC, which hold more promise for various potential applications. © 2016 Elsevier B.V. All rights reserved.

  18. Innovative Self-Healing Seals for Solid Oxide Fuel Cells (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Raj Singh

    2012-06-30

    Solid oxide fuel cell (SOFC) technology is critical to several national initiatives. Solid State Energy Conversion Alliance (SECA) addresses the technology needs through its comprehensive programs on SOFC. A reliable and cost-effective seal that works at high temperatures is essential to the long-term performance of the SOFC for 40,000 hours at 800°C. Consequently, seals remain an area of highest priority for the SECA program and its industry teams. An innovative concept based on self-healing glasses was advanced and successfully demonstrated through seal tests for 3000 hours and 300 thermal cycles to minimize internal stresses under both steady state and thermal transients for making reliable seals for the SECA program. The self-healing concept requires glasses with low viscosity at the SOFC operating temperature of 800°C but this requirement may lead to excessive flow of the glass in areas forming the seal. To address this challenge, a modification to glass properties by addition of particulate fillers is pursued in the project. The underlying idea is that a non-reactive ceramic particulate filler is expected to form glass-ceramic composite and increase the seal viscosity thereby increasing the creep resistance of the glass-composite seals under load. The objectives of the program are to select appropriate filler materials for making glass-composite, fabricate glass-composites, measure thermal expansion behaviors, and determine stability of the glass-composites in air and fuel environments of a SOFC. Self-healing glass-YSZ composites are further developed and tested over a longer time periods under conditions typical of the SOFCs to validate the long-term stability up to 2000 hours. The new concepts of glass-composite seals, developed and nurtured in this program, are expected to be cost-effective as these are based on conventional processing approaches and use of the inexpensive materials.

  19. Thermal and Ash Characterization of Indonesian Bamboo and Its Potential for Solid Fuel and Waste Valorization

    Directory of Open Access Journals (Sweden)

    Aprilina Purbasari

    2016-08-01

    Full Text Available Bamboo has been widely used in Indonesia for construction, handicrafts, furniture and other uses. However, the use of bamboo as a biomass for renewable energy source has not been extensively explored. This paper describes the thermal and ash characterization of three bamboo species found in Indonesia, i.e. Gigantochloa apus, Gigantochloa levis and Gigantochloa atroviolacea. Characterization of bamboo properties as a solid fuel includes proximate and ultimate analyses, calorific value measurement and thermogravimetric analysis. Ash characterization includes oxide composition analysis and phase analysis by X-Ray diffraction. The selected bamboo species have calorific value comparable with wood with low nitrogen and sulphur contents, indicating that they can be used as renewable energy sources. Bamboo ash contains high silicon so that bamboo ash has potential to be used further as building materials or engineering purposes. Ash composition analysis also indicates high alkali that can cause ash sintering and slag formation in combustion process. This implies that the combustion of bamboo requires the use of additives to reduce the risk of ash sintering and slag formation. Article History: Received May 15, 2016; Received in revised form July 2nd, 2016; Accepted July 14th, 2016; Available online How to Cite This Article: Purbasari, A., Samadhi, T.W. & Bindar, Y. (2016 Thermal and Ash Characterization of Indonesian Bamboo and its Potential for Solid Fuel and Waste Valorization. Int. Journal of Renewable Energy Development, 5(2, 95-100. http://dx.doi.org/10.14710/ijred.5.2.96-100 

  20. Micro solid oxide fuel cells: a new generation of micro-power sources for portable applications

    Science.gov (United States)

    Chiabrera, Francesco; Garbayo, Iñigo; Alayo, Nerea; Tarancón, Albert

    2017-06-01

    Portable electronic devices are already an indispensable part of our daily life; and their increasing number and demand for higher performance is becoming a challenge for the research community. In particular, a major concern is the way to efficiently power these energy-demanding devices, assuring long grid independency with high efficiency, sustainability and cheap production. In this context, technologies beyond Li-ion are receiving increasing attention, among which the development of micro solid oxide fuel cells (μSOFC) stands out. In particular, μSOFC provides a high energy density, high efficiency and opens the possibility to the use of different fuels, such as hydrocarbons. Yet, its high operating temperature has typically hindered its application as miniaturized portable device. Recent advances have however set a completely new range of lower operating temperatures, i.e. 350-450°C, as compared to the typical <900°C needed for classical bulk SOFC systems. In this work, a comprehensive review of the status of the technology is presented. The main achievements, as well as the most important challenges still pending are discussed, regarding (i.) the cell design and microfabrication, and (ii.) the integration of functional electrolyte and electrode materials. To conclude, the different strategies foreseen for a wide deployment of the technology as new portable power source are underlined.

  1. Training Course of Experimental Chemistry in the Nuclear Fuel Cycle: Solid State and Solution Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ju hyeong; Park, Kwangheon; Kim, Tae hoon; Park, Hyoung gyu; Kim, Jisu [Kyunghee University, Yongin (Korea, Republic of); Song, Hyuk jin [Dongguk University, Gyeongju (Korea, Republic of); Lee, Chan ki; Kang, Do kyu; Jeong, Hyeon jun [UNIST, Ulsan (Korea, Republic of)

    2016-10-15

    In this experimental study program in Tohoku University, basic experiments were done by the participants. First one is the hydrogen reduction experiment of the mixture of UO{sub 2} and ZrO{sub 2}. Second one is to observe microscopic structure of solid solution of UO{sub 2} and ZrO{sub 2} using SEM/EDX and XRD system, simulated fuel debris. Third one is milking process of {sup 239}Np from {sup 243}Am by solvent extraction using Tri-n-Octylamine (TOA). Last one is solvent extraction in PUREX by the simulated mixed aqueous solution of U, {sup 85}Sr and {sup 239}Np which is represented minor actinide elements included in the spent nuclear fuel. Uranium is separated from aqueous phase to organic phase during solvent extraction procedure using TBP and dodecane. Also, neptunium can be extracted to organic phase as nitric acid concentration change. The extraction behavior of neptunium is different by oxidation state in aqueous phase. The behavior of neptunium is represented as a combined form of these oxidation states in experiment. Therefore, because the oxidation states of neptunium can be controlled by controlling the concentration of nitric acid, the extractability of neptunium can be controlled.

  2. Process simulation of biomass gasification integrated with a solid oxide fuel cell stack

    Science.gov (United States)

    Doherty, Wayne; Reynolds, Anthony; Kennedy, David

    2015-03-01

    Biomass gasification-solid oxide fuel cell (BG-SOFC) combined heat and power (CHP) systems are of major interest in the context of climate change mitigation, energy security and increasing energy efficiency. Aspen Plus is employed to simulate various BG-SOFC CHP systems. The aim of the research work is to investigate the technical feasibility of these systems and to study the influence of important operating parameters and examine integration options. Systems based on dual fluidised bed steam gasification and tubular SOFC technologies are modelled. The cathode recycle and electric heater integration options are not attractive in comparison to the base case anode recycle system. Thermal integration, i.e. using SOFC flue gas as gasifier oxidant, is desirable. Lowering the syngas preheat temperature (prior to SOFC anodes) is highly recommended and is more practical than lowering the cathode air preheat temperature. Results of the parametric study indicate that: steam to carbon ratio and biomass moisture content should be as low as possible; fuel utilisation factor can change the mode of operation of the plant (focus on electricity or heat); high temperature syngas cleaning is very attractive; gasification air preheating is more attractive than gasification steam superheating. High efficiencies are predicted, proving the technical feasibility of BG-SOFC CHP systems.

  3. In situ, simultaneous thermal imaging and infrared molecular emission studies of solid oxide fuel cell electrodes

    Science.gov (United States)

    Kirtley, J. D.; Qadri, S. N.; Steinhurst, D. A.; Owrutsky, J. C.

    2016-12-01

    Various in situ probes of solid oxide fuel cells (SOFCs) have advanced recently to provide detailed, real time data regarding materials and chemical processes that relate to device performance and degradation. These techniques offer insights into complex fuel chemistry at the anode in particular, especially in the context of model predictions. However, cell-to-cell variations can hinder mechanistic interpretations of measurements from separate, independent techniques. The present study describes an in situ technique that for the first time simultaneously measures surface temperature changes using near infrared thermal imaging and gas species using Fourier-transform infrared emission spectra at the anodes of operating SOFCs. Electrolyte-supported SOFCs with Ni-based anodes are operated at 700 °C with internal, dry-reformed methane at 75% maximum current and at open circuit voltage (OCV) while electrochemical and optical measurements are collected. At OCV, more cooling is observed coincident with more CO reforming products. Under load, CO decreases while the anode cools less, especially near the current collectors. The extent of cooling is more sensitive to polarization for electrolyte-supported cells because their anodes are thinner relative to anode-supported cells. This study exemplifies how this duplex technique can be a useful probe of electrochemical processes in SOFCs.

  4. Direct operation of Ag-based anode solid oxide fuel cells on propane

    Science.gov (United States)

    Zhang, Yapeng; Yu, Fangyong; Wang, Xiaoqiang; Zhou, Qian; Liu, Jiang; Liu, Meilin

    2017-10-01

    A cermet of sliver and gadolinium-doped ceria (GDC) is investigated as the anode material of solid oxide fuel cells (SOFCs). The SOFCs are operated with hydrogen and dry propane as the fuel and ambient air as the oxidant. Their electrochemical and durability performances are tested and compared to those of SOFCs with conventional Ni-GDC anode. Experimental results show that performances of the SOFCs, respectively with Ag-GDC and Ni-GDC anode, are similar when operated on hydrogen, while quite different on propane. The open circuit voltage (OCV) of a SOFC with Ag-GDC anode is stable at ∼1 V while that with Ni-GDC anode continuously drops from the initial 1.2 V-0.85 V in 140 min. A SOFC with Ag-GDC anode has been stably operated on propane at a constant current density of 103 mA cm-2 for more than 160 h while that with Ni-GDC anode for only 50 h. SEM examination shows Ni-GDC anode is destroyed by carbon deposition during operation on propane, while Ag-GDC anode is well conserved and has a carbon layer, with some breakages, built on its surface. Mechanisms of the stable operation of SOFCs with Ag-GDC anode on dry propane is investigated and analyzed.

  5. Thermomechanical analysis of porous solid oxide fuel cell by using peridynamics

    Directory of Open Access Journals (Sweden)

    Hanlin Wang

    2017-06-01

    Full Text Available Solid oxide fuel cell (SOFC is widely used in hybrid marine propulsion systems due to its high power output, excellent emission control and wide fuel suitability. However, the operating temperature in SOFC will rise up to 800–1000 ℃ due to redox reaction among hydrogen and oxygen ions. This provides a suitable environment for ions transporting through ceramic materials. Under such operation temperatures, degradation may occur in the electrodes and electrolyte. As a result, unstable voltage, low capacity and cell failure may eventually occur. This study presents thermomechanical analysis of a porous SOFC cell plate which contains electrodes, electrolytes and pores. A microscale specimen in the shape of a plate is considered in order to maintain uniform temperature loading and increase the accuracy of estimation. A new computational technique, peridynamics, is utilized to calculate the deformations and stresses of the cell plate. Moreover, the crack formation and propagation are also obtained by using peridynamics. According to the numerical results, damage evolution depends on the electrolyte/electrode interface strength during the charging process. For weak interface strength case, damage emerges at the electrode/electrolyte interface. On the other hand, for stronger interface cases, damage emerges on pore boundaries especially with sharp corner.

  6. Operational Concept Evaluation of Solid Oxide Fuel Cells for Space Vehicle Applications

    Science.gov (United States)

    Poast, Kenneth I.

    2011-01-01

    With the end of the Space Shuttle Program, NASA is evaluating many different technologies to support future missions. Green propellants, like liquid methane and liquid oxygen, have potential advantages for some applications. A Lander propelled with LOX/methane engines is one such application. When the total vehicle design and infrastructure are considered, the advantages of the integration of propulsion, heat rejection, life support and power generation become attractive for further evaluation. Scavenged residual propellants from the propulsion tanks could be used to generate needed electric power, heat and water with a Solid Oxide Fuel Cell(SOFC). In-Situ Resource Utilization(ISRU) technologies may also generate quantities of green propellants to refill these tanks and/or supply these fuel cells. Technology demonstration projects such as the Morpheus Lander are currently underway to evaluate the practicality of such designs and operational concepts. Tethered tests are currently in progress on this vertical test bed to evaluate the propulsion and avionics systems. Evaluation of the SOFC seeks to determine the feasibility of using these green propellants to supply power and identify the limits to the integration of this technology into a space vehicle prototype.

  7. Optimization of the Interconnect Ribs for a Cathode-Supported Solid Oxide Fuel Cell

    Directory of Open Access Journals (Sweden)

    Wei Kong

    2014-01-01

    Full Text Available A comprehensive mathematical model of the performance of the cathode-supported solid oxide fuel cell (SOFC with syngas fuel is presented. The model couples the intricate interdependency between the ionic conduction, electronic conduction, gas transport, the electrochemical reaction processes in the functional layers and on the electrode/electrolyte interfaces, methane steam reforming (MSR and the water gas shift reaction (WGSR. The validity of the mathematical model is demonstrated by the excellent agreement between the numerical and experimental I-V curves. The effect of anode rib width and cathode rib width on gas diffusion and cell performance is examined. The results show conclusively that the cell performance is strongly influenced by the rib width. Furthermore, the anode optimal rib width is smaller than that for cathode, which is contrary to anode-supported SOFC. Finally, the formulae for the anode and cathode optimal rib width are given, which provide an easy to use guidance for the broad SOFC engineering community.

  8. Optimal robust control strategy of a solid oxide fuel cell system

    Science.gov (United States)

    Wu, Xiaojuan; Gao, Danhui

    2018-01-01

    Optimal control can ensure system safe operation with a high efficiency. However, only a few papers discuss optimal control strategies for solid oxide fuel cell (SOFC) systems. Moreover, the existed methods ignore the impact of parameter uncertainty on system instantaneous performance. In real SOFC systems, several parameters may vary with the variation of operation conditions and can not be identified exactly, such as load current. Therefore, a robust optimal control strategy is proposed, which involves three parts: a SOFC model with parameter uncertainty, a robust optimizer and robust controllers. During the model building process, boundaries of the uncertain parameter are extracted based on Monte Carlo algorithm. To achieve the maximum efficiency, a two-space particle swarm optimization approach is employed to obtain optimal operating points, which are used as the set points of the controllers. To ensure the SOFC safe operation, two feed-forward controllers and a higher-order robust sliding mode controller are presented to control fuel utilization ratio, air excess ratio and stack temperature afterwards. The results show the proposed optimal robust control method can maintain the SOFC system safe operation with a maximum efficiency under load and uncertainty variations.

  9. Exergy Analysis of Solid Fuel-Fired Heat and Power Plants: A Review

    Directory of Open Access Journals (Sweden)

    Francis Chinweuba Eboh

    2017-02-01

    Full Text Available The growing demand for energy is particularly important to engineers with respect to how the energy produced by heat and power plants can be used efficiently. Formerly, performance evaluation of thermal power plants was done through energy analysis. However, the energy method does not account for irreversibilities within the system. An effective method to measure and improve efficiency of thermal power plant is exergy analysis. Exergy analysis is used to evaluate the performance of a system and its main advantage is enhancement of the energy conversion process. It helps identify the main points of exergy destruction, the quantity and causes of this destruction, as well as show which areas in the system and components have potential for improvements. The current study is a comprehensive review of exergy analyses applied in the solid fuels heat and power sector, which includes coal, biomass and a combination of these feedstocks as fuels. The methods for the evaluation of the exergy efficiency and the exergy destruction are surveyed in each part of the plant. The current review is expected to advance understanding of exergy analysis and its usefulness in the energy and power sectors: it will assist in the performance assessment, analysis, optimization and cost effectiveness of the design of heat and power plant systems in these sectors.

  10. The Swedish Ash Programme 2002-2008. Biomass, wastes, peat - any solid fuel but coal

    Energy Technology Data Exchange (ETDEWEB)

    Bjurstroem, Henrik; Herbert, Roger

    2009-07-15

    In Sweden, producers of combustion residues have since 2002 implemented a collaborative applied RandD programme aimed at the utilisation of combustion residues (ash). The fuels are biomass, wastes, peat - any solid fuel but coal. In this report, the main lines of the programme are described: Covers for landfills and mine tailings; Civil works, e.g. road-buildings, where both geotechnical and environmental questions have been addressed; Cement and concrete applications; Compensating soils for removing biomass and the mineral nutrients in the biomass. The emphasis of the Programme is on environmental questions, even if technical questions have been treated. The time perspective in this context is much longer than the 3-5 years that are usual in an applied RandD programme, i.e. decades after ash has been placed on a site, e.g. in a road, or spread to forest soil. New test fields have been created in the programme and old test fields have been evaluated in order to gather available information

  11. Mass and Heat Transfer in Ion-Exchange Membranes Applicable to Solid Polymer Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Otteroey, M.

    1996-04-01

    In this doctoral thesis, an improved emf method for determination of transference numbers of two counter ions in ion-exchange membranes is presented. Transference numbers were obtained as a continuous function of the composition. The method avoids problems with diffusion by using a stack of membranes. Water transference coefficients in ion-exchange membranes is discussed and reversible and irreversible water transfer is studied by emf methods. Efforts were made to get data relevant to the solid polymer fuel cell. The results support the findings of other researchers that the reversible water transfer is lower than earlier predicted. A chapter on the conductivity of ion-exchange membranes establishes a method to separate the very thin liquid layers surrounding the membranes in a stack. Using the method it was found that the conductivity is obtained with high accuracy and that the liquid layer in a membrane stack can contribute significantly to the total measured resistance. A four point impedance method was tested to measure the conductivity of membranes under fuel cell conditions. Finally, there is a discussion of reversible heat effects and heat transfer in ion-exchange membranes. 155 refs., 45 figs., 13 tabs.

  12. Fine grain separation for the production of biomass fuel from mixed municipal solid waste.

    Science.gov (United States)

    Giani, H; Borchers, B; Kaufeld, S; Feil, A; Pretz, T

    2016-01-01

    The main goal of the project MARSS (Material Advanced Sustainable Systems) is to build a demonstration plant in order to recover a renewable biomass fuel suitable for the use in biomass power plants out of mixed municipal solid waste (MMSW). The demonstration plant was constructed in Mertesdorf (Germany), working alongside an existing mechanical-biological treatment plant, where the MMSW is biological dried under aerobe conditions in rotting boxes. The focus of the presented sorting campaign was set on the processing of fine grain particles minor than 11.5mm which have the highest mass content and biogenic energy potential of the utilized grain size fractions. The objective was to produce a biomass fuel with a high calorific value and a low content of fossil (plastic, synthetic) materials while maximizing the mass recovery. Therefore, the biogenic components of the dried MMSW are separated from inert and fossil components through various classification and sifting processes. In three experimental process setups of different processing depths, the grain size fraction 4-11.5mm was sifted by the use of air sifters and air tables. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Catalytic and electrochemical behaviour of solid oxide fuel cell operated with simulated-biogas mixtures

    Energy Technology Data Exchange (ETDEWEB)

    Dang-Long, T., E-mail: 3TE14098G@kyushu-u.ac.jp [Department of Hydrogen Energy Systems, Faculty of Engineering, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan); Quang-Tuyen, T., E-mail: tran.tuyen.quang.314@m.kyushu-u.ac.jp [International Research Center for Hydrogen Energy, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan); Shiratori, Y., E-mail: shiratori.yusuke.500@m.kyushu-u.ac.jp [Department of Hydrogen Energy Systems, Faculty of Engineering, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan); International Research Center for Hydrogen Energy, Kyushu University Motooka 744, Nishiku, Fukuoka, 810-0395 (Japan)

    2016-06-03

    Being produced from organic matters of wastes (bio-wastes) through a fermentation process, biogas mainly composed of CH{sub 4} and CO{sub 2} and can be considered as a secondary energy carrier derived from solar energy. To generate electricity from biogas through the electrochemical process in fuel cells is a state-of-the-art technology possessing higher energy conversion efficiency without harmful emissions compared to combustion process in heat engines. Getting benefits from high operating temperature such as direct internal reforming ability and activation of electrochemical reactions to increase overall system efficiency, solid oxide fuel cell (SOFC) system operated with biogas becomes a promising candidate for distributed power generator for rural applications leading to reductions of environmental issues caused by greenhouse effects and bio-wastes. CO{sub 2} reforming of CH{sub 4} and electrochemical oxidation of the produced syngas (H{sub 2}–CO mixture) are two main reaction processes within porous anode material of SOFC. Here catalytic and electrochemical behavior of Ni-ScSZ (scandia stabilized-zirconia) anode in the feed of CH{sub 4}–CO{sub 2} mixtures as simulated-biogas at 800 °C were evaluated. The results showed that CO{sub 2} had strong influences on both reaction processes. The increase in CO{sub 2} partial pressure resulted in the decrease in anode overvoltage, although open-circuit voltage was dropped. Besides that, the simulation result based on a power-law model for equimolar CH{sub 4}−CO{sub 2} mixture revealed that coking hazard could be suppressed along the fuel flow channel in both open-circuit and closed-circuit conditions.

  14. Combustion of Solid Fuel in a Vortex Furnace with Counter-swirling Flows

    Directory of Open Access Journals (Sweden)

    Redko A.A.

    2017-12-01

    Full Text Available The results of computer simulation of the processes of incineration of low-grade solid fuel-pulverized peat with a moisture content of 40%, an ash content of 6% are given. It has been determined the fields of distribution of temperature, velocity of gases and particles in the volume and at the outlet from the furnace. The three-dimensional temperature distribution in the combustion chamber indicates high-temperature combustion of peat particles at temperatures above 1700°C with liquid ash removal in the lower part of the furnace. It has been determined that when the furnace is cooled, it is not ensured combustion of the fuel completely. The value of the swirling flow rate at the outlet from the furnace (up to 370 m/s ensures the efficiency of separation of fuel particles, reducing heat losses from mechanical underburning. It is determined that the concentration of oxygen is close to zero over the entire height of the furnace, at an outlet from the furnace the oxygen concentration is 5...6%, since oxygen is supplied with excess (αв=1,2. The results of a numerical study showed that the diameter of peat particles affects the process of their combustion: coke particles with an initial diameter of 25 mkm to 250 mkm burn out by 96%. With an increase in particle diameter up to 1000 mkm, the degree of burn-out of coke decreases, but at the same time their removal decreases. It is shown that the furnace ensures the completeness of combustion of peat particles of peat 99.8%, volatiles is 100%.

  15. Catalytic and electrochemical behaviour of solid oxide fuel cell operated with simulated-biogas mixtures

    Science.gov (United States)

    Dang-Long, T.; Quang-Tuyen, T.; Shiratori, Y.

    2016-06-01

    Being produced from organic matters of wastes (bio-wastes) through a fermentation process, biogas mainly composed of CH4 and CO2 and can be considered as a secondary energy carrier derived from solar energy. To generate electricity from biogas through the electrochemical process in fuel cells is a state-of-the-art technology possessing higher energy conversion efficiency without harmful emissions compared to combustion process in heat engines. Getting benefits from high operating temperature such as direct internal reforming ability and activation of electrochemical reactions to increase overall system efficiency, solid oxide fuel cell (SOFC) system operated with biogas becomes a promising candidate for distributed power generator for rural applications leading to reductions of environmental issues caused by greenhouse effects and bio-wastes. CO2 reforming of CH4 and electrochemical oxidation of the produced syngas (H2-CO mixture) are two main reaction processes within porous anode material of SOFC. Here catalytic and electrochemical behavior of Ni-ScSZ (scandia stabilized-zirconia) anode in the feed of CH4-CO2 mixtures as simulated-biogas at 800 °C were evaluated. The results showed that CO2 had strong influences on both reaction processes. The increase in CO2 partial pressure resulted in the decrease in anode overvoltage, although open-circuit voltage was dropped. Besides that, the simulation result based on a power-law model for equimolar CH4-CO2 mixture revealed that coking hazard could be suppressed along the fuel flow channel in both open-circuit and closed-circuit conditions.

  16. Study utilization of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuels

    Science.gov (United States)

    Hendrianie, Nuniek; Juliastuti, Sri Rachmania; Ar-rosyidah, Fanny Husna; Rochman, Hilal Abdur

    2017-05-01

    Nowadays the existence of energy sources of oil and was limited. Therefore, it was important to searching for new innovations of renewable energy sources by utilizing the waste into a source of energy. On the other hand, the process of extractable petroleum hydrocarbons biodegradation generated sludge that had calorific value and untapped. Because of the need for alternative sources of energy innovation with the concept of zero waste and the fuel potential from extractable petroleum hydrocarbons biodegradation waste, so it was necessary to study the use of extractable petroleum hydrocarbons biodegradation waste as the main material for making solid fuel. In addition, sawdust is a waste that had a great quantities and also had a high calorific value to be mixed with extractable petroleum hydrocarbons biodegradation waste. The purpose of this study was to determine the characteristics of the extractable petroleum hydrocarbons biodegradation waste and to determine the potential and a combination of a mixture of extractable petroleum hydrocarbons biodegradation waste and sawdust which has the best calorific value. The variables of this study was the composition of the waste and sawdust as follows 1:1; 1:3; and 3:1 (mass of sawdust : mass of waste) and time of sawdust carbonization was 10, 15 and 20 minutes. Sawdust was carbonized to get the high heating value. The characteristic of main material and fuel analysis performed with proximate analysis. While the calorific value analysis was performed with a bomb calorimeter. From the research, it was known that extractable petroleum hydrocarbons biodegradation waste had a moisture content of 3.06%; volatile matter 19.98%; ash content of 0.56%; fixed carbon content of 76.4% and a calorific value of 717 cal/gram. And a mixture that had the highest calorific value (4286.5 cal/gram) achieved in comparison sawdust : waste (3:1) by carbonization of sawdust for 20 minutes.

  17. Solid recovered fuels in the cement industry with special respect to hazardous waste.

    Science.gov (United States)

    Thomanetz, Erwin

    2012-04-01

    Cements with good technical properties have been produced in Europe since the nineteenth century and are now worldwide standardized high-quality mass products with enormous production numbers. The basic component for cement is the so-called clinker which is produced mainly from raw meal (limestone plus clay plus sands) in a rotary kiln with preheater and progressively with integrated calciner, at temperatures up to 1450 °C. This process requires large amounts of fossil fuels and is CO₂-intensive. But most CO₂ is released by lime decomposition during the burning process. In the 1980s the use of alternative fuels began--firstly in the form of used oil and waste tyres and then increasingly by pre-conditioned materials from commercial waste and from high calorific industrial waste (i.e. solid recovered fuel (SRF))--as well as organic hazardous waste materials such as solvents, pre-conditioned with sawdust. Therefore the cement industry is more and more a competitor in the waste-to-energy market--be it for municipal waste or for hazardous waste, especially concerning waste incineration, but also for other co-incineration plants. There are still no binding EU rules identifying which types of SRF or hazardous waste could be incinerated in cement kilns, but there are some well-made country-specific 'positive lists', for example in Switzerland and Austria. Thus, for proper planning in the cement industry as well as in the waste management field, waste disposal routes should be considered properly, in order to avoid surplus capacities on one side and shortage on the other.

  18. Regenerative Performance of the NASA Symmetrical Solid Oxide Fuel Cell Design

    Science.gov (United States)

    Cable, Thomas L.; Setlock, John A.; Farmer, Serene C.; Eckel, Andy J.

    2009-01-01

    The NASA Glenn Research Center is developing both a novel cell design (BSC) and a novel ceramic fabrication technique to produce fuel cells predicted to exceed a specific power density of 1.0 kW/kg. The NASA Glenn cell design has taken a completely different approach among planar designs by removing the metal interconnect and returning to the use of a thin, doped LaCrO3 interconnect. The cell is structurally symmetrical. Both electrodes support the thin electrolyte and contain micro-channels for gas flow-- a geometry referred to as a bi-electrode supported cell or BSC. The cell characteristics have been demonstrated under both SOFC and SOE conditions. Electrolysis tests verify that this cell design operates at very high electrochemical voltage efficiencies (EVE) and high H2O conversion percentages, even at the low flow rates predicted for closed loop systems encountered in unmanned aerial vehicle (UAV) applications. For UAVs the volume, weight and the efficiency are critical as they determine the size of the water tank, the solar panel size, and other system requirements. For UAVs, regenerative solid oxide fuel cell stacks (RSOFC) use solar panels during daylight to generate power for electrolysis and then operate in fuel cell mode during the night to power the UAV and electronics. Recent studies, performed by NASA for a more electric commercial aircraft, evaluated SOFCs for auxiliary power units (APUs). System studies were also conducted for regenerative RSOFC systems. One common requirement for aerospace SOFCs and RSOFCs, determined independently in each application study, was the need for high specific power density and volume density, on the order of 1.0 kW/kg and greater than 1.0 kW/L. Until recently the best reported performance for SOFCs was 0.2 kW/kg or less for stacks. NASA Glenn is working to prototype the light weight, low volume BSC design for such high specific power aerospace applications.

  19. Anode-pore tortuosity in solid oxide fuel cells found from gas and current flow rates

    Science.gov (United States)

    Schmidt, V. Hugo; Tsai, Chih-Long

    The effect of solid oxide fuel cell (SOFC) anode thickness, porosity, pore size, and pore tortuosity on fuel and exhaust gas flow is calculated. Also determined is the concentration of these gases and of diluent gases as a function of position across the anode. The calculation is based on the dusty-gas model which includes a Knudsen (molecule-wall) collision term in the Stefan-Maxwell equation which is based on unlike-molecule collisions. Commonly made approximations are avoided in order to obtain more exact results. One such approximation is the assumption of uniform total gas pressure across the anode. Another such approximation is the assumption of zero fuel gas concentration at the anode-electrolyte interface under the anode saturation condition for which the SOFC output voltage goes to zero. Elimination of this approximation requires use of a model we developed (published elsewhere) for terminal voltage V as a function of electrolyte current density i. Key formulae from this model are presented. The formulae developed herein for gas flow and tortuosity are applied to the results of a series of careful experiments performed by another group, who used binary and ternary gas mixtures on the anode side of an SOFC. Our values for tortuosity are in a physically reasonable low range, from 1.7 to 3.3. They are in fair agreement with those obtained by the other group, once a difference in nomenclature is taken into account. This difference consists in their definition of tortuosity being what some call tortuosity factor, which is the square of what we and some others call tortuosity. The results emphasize the need for careful design of anode pore structures, especially in anode-supported SOFCs which require thicker anodes.

  20. Torrefaction study for energy upgrading on Indonesian biomass as low emission solid fuel

    Science.gov (United States)

    Alamsyah, R.; Siregar, N. C.; Hasanah, F.

    2017-05-01

    Torrefaction is a pyrolysis process with low heating rate and temperature lower than 300°C in an inert condition which transforms biomass into a low emission solid fuel with relatively high energy. Through the torrefaction process biomass can be altered so that the end product is easy to grind and simple in the supply chain. The research was aimed at designing torrefaction reactor and upgrading energy content of some Indonesian biomass. The biomass used consist of empty fruit bunches of oil palm (EFB), cassava peel solid waste, and cocopeat (waste of coconut fiber). These biomass were formed into briquette and pellet form and were torrified with 300°C temperature during 1.5 hours without air. The results of terrified biomass and non-torrefied biomass were compared after burning on the stove in term of energy content and air emission quality. The result shows that energy content of biomass have increased by 1.1 up to 1.36 times. Meanwhile emission air resulted from its combustion was met with Indonesian emission regulation.

  1. A Supply-Chain Analysis Framework for Assessing Densified Biomass Solid Fuel Utilization Policies in China

    Directory of Open Access Journals (Sweden)

    Wenyan Wang

    2015-07-01

    Full Text Available Densified Biomass Solid Fuel (DBSF is a typical solid form of biomass, using agricultural and forestry residues as raw materials. DBSF utilization is considered to be an alternative to fossil energy, like coal in China, associated with a reduction of environmental pollution. China has abundant biomass resources and is suitable to develop DBSF. Until now, a number of policies aimed at fostering DBSF industry have been proliferated by policy makers in China. However, considering the seasonality and instability of biomass resources, these inefficiencies could trigger future scarcities of biomass feedstocks, baffling the resilience of biomass supply chains. Therefore, this review paper focuses on DBSF policies and strategies in China, based on the supply chain framework. We analyzed the current developing situation of DBSF industry in China and developed a framework for policy instruments based on the supply chain steps, which can be used to identify and assess the deficiencies of current DBSF industry policies, and we proposed some suggestions. These findings may inform policy development and identify synergies at different steps in the supply chain to enhance the development of DBSF industry.

  2. Influence of temperature and atmosphere on the strength and elastic modulus of solid oxide fuel cell anode supports

    DEFF Research Database (Denmark)

    Ni, De Wei; Charlas, Benoit; Kwok, Kawai

    2016-01-01

    Solid Oxide Fuel Cells are subjected to significant stresses during production and operation. The various stress-generating conditions impose strength requirements on the cell components, and thus the mechanical properties of the critical load bearing materials at relevant operational conditions ...

  3. Impact of passive smoking, cooking with solid fuel exposure, and MBL/MASP-2 gene polymorphism upon susceptibility to tuberculosis

    Directory of Open Access Journals (Sweden)

    Mengshi Chen

    2014-12-01

    Conclusions: Passive smoking, cooking with solid fuel, and polymorphisms of MBL (rs7096206 and MASP-2 (rs6695096 genes were associated with susceptibility to TB in non-smokers, and there were gene–environment interactions among them. Further studies are needed to explore details of the mechanisms of association.

  4. Highlights from Faraday Discussion 182: Solid Oxide Electrolysis: Fuels and Feedstocks from Water and Air, York, UK, July 2015.

    Science.gov (United States)

    Stefan, Elena; Norby, Truls

    2016-01-31

    The rising importance of converting high peak electricity from renewables to fuels has urged field specialists to organize this Faraday Discussion on Solid Oxide Electrolysis. The topic is of essential interest in order to achieve a greater utilization of renewable energy and storage at higher densities.

  5. Municipal solid waste conversion to transportation fuels: a life-cycle estimation of global warming potential and energy consumption

    DEFF Research Database (Denmark)

    Pressley, Phillip N.; Aziz, Tarek N.; DeCarolis, Joseph F.

    2014-01-01

    This paper utilizes life cycle assessment (LCA) methodology to evaluate the conversion of U.S. municipal solid waste (MSW) to liquid transportation fuels via gasification and Fischer-Tropsch (FT). The model estimates the cumulative energy demand and global warming potential (GWP) associated...

  6. Exergy analysis and optimization of a biomass gasification, solid oxide fuel cell and micro gas turbine hybrid system

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud; Elmegaard, Brian

    2011-01-01

    A hybrid plant producing combined heat and power (CHP) from biomass by use of a two-stage gasification concept, solid oxide fuel cells (SOFC) and a micro gas turbine was considered for optimization. The hybrid plant represents a sustainable and efficient alternative to conventional decentralized...

  7. Thermodynamic and thermoeconomic analysis of a system with biomass gasification, solid oxide fuel cell (SOFC) and Stirling engine

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2014-01-01

    Thermodynamic and thermoeconomic investigations of a small-scale integrated gasification solid oxide fuel cell (SOFC) and Stirling engine for combined heat and power (CHP) with a net electric capacity of 120kWe have been performed. Woodchips are used as gasification feedstock to produce syngas...

  8. Modelling of a Biomass Gasification Plant Feeding a Hybrid Solid Oxide Fuel Cell and Micro Gas Turbine System

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud

    2009-01-01

    A system level modelling study on two combined heat and power (CHP) systems both based on biomass gasification. One system converts the product gas in a solid oxide fuel cell (SOFC) and the other in a combined SOFC and micro gas turbine (MGT) arrangement. An electrochemical model of the SOFC has...

  9. Modelling a Combined Heat and Power Plant based on Gasification, Micro Gas Turbine and Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Bang-Møller, Christian; Rokni, Masoud

    2009-01-01

    A system level modelling study on two combined heat and power (CHP) systems both based on biomass gasification. One system converts the product gas in a micro gas turbine (MGT) and the other in a combined solid oxide fuel cell (SOFC) and MGT arrangement. An electrochemical model of the SOFC has...

  10. On the Properties and Long-Term Stability of Infiltrated Lanthanum Cobalt Nickelates (LCN) in Solid Oxide Fuel Cell Cathodes

    DEFF Research Database (Denmark)

    Kiebach, Wolff-Ragnar; Zielke, Philipp; Veltzé, Sune

    2017-01-01

    Infiltration as a fabrication method for solid oxide fuel cells (SOFC) electrodes is offering significant improvements in cell performance at reduced materials and fabrication costs, especially when combined with co-sintering. However, important questions regarding the long-term performance...

  11. Effect of proton-conduction in electrolyte on electric efficiency of multi-stage solid oxide fuel cells

    Science.gov (United States)

    Matsuzaki, Yoshio; Tachikawa, Yuya; Somekawa, Takaaki; Hatae, Toru; Matsumoto, Hiroshige; Taniguchi, Shunsuke; Sasaki, Kazunari

    2015-01-01

    Solid oxide fuel cells (SOFCs) are promising electrochemical devices that enable the highest fuel-to-electricity conversion efficiencies under high operating temperatures. The concept of multi-stage electrochemical oxidation using SOFCs has been proposed and studied over the past several decades for further improving the electrical efficiency. However, the improvement is limited by fuel dilution downstream of the fuel flow. Therefore, evolved technologies are required to achieve considerably higher electrical efficiencies. Here we present an innovative concept for a critically-high fuel-to-electricity conversion efficiency of up to 85% based on the lower heating value (LHV), in which a high-temperature multi-stage electrochemical oxidation is combined with a proton-conducting solid electrolyte. Switching a solid electrolyte material from a conventional oxide-ion conducting material to a proton-conducting material under the high-temperature multi-stage electrochemical oxidation mechanism has proven to be highly advantageous for the electrical efficiency. The DC efficiency of 85% (LHV) corresponds to a net AC efficiency of approximately 76% (LHV), where the net AC efficiency refers to the transmission-end AC efficiency. This evolved concept will yield a considerably higher efficiency with a much smaller generation capacity than the state-of-the-art several tens-of-MW-class most advanced combined cycle (MACC). PMID:26218470

  12. Experimental investigation of solid oxide fuel cells using biomass gasification producer gases

    Energy Technology Data Exchange (ETDEWEB)

    Norheim, Arnstein

    2005-07-01

    The main objective of this thesis is theoretical and experimental investigations related to utilisation of biomass gasification producer gases as fuel for Solid Oxide Fuel Cells (SOFC). Initial fundamental steps towards a future system of combined heat and power production based on biomass gasification and SOFC are performed and include: 1) Theoretical modeling of the composition of biomass gasification producer gases. 2) Experimental investigation of SOFC performance using biomass gasification producer gas as fuel. 3) Experimental investigation of SOFC performance using biomass gasification producer gas containing high sulphur concentration. The modeling of the composition of gasifier producer gas was performed using the program FactSage. The main objective was to investigate the amount and speciation of trace species in the producer gases as several parameters were varied. Thus, the composition at thermodynamic equilibrium of sulphur, chlorine, potassium, sodium and compounds of these were established. This was done for varying content of the trace species in the biomass material at different temperatures and fuel utilisation i.e. varying oxygen content in the producer gas. The temperature interval investigated was in the range of normal SOFC operation. It was found that sulphur is expected to be found as H2S irrespective of temperature and amount of sulphur. Only at very high fuel utilisation some S02 is formed. Important potassium containing compounds in the gas are gaseous KOH and K. When chlorine is present, the amount of KOH and K will decrease due to the formation of KCI. The level of sodium investigated here was low, but some Na, NaOH and NaCl is expected to be formed. Below a certain temperature, condensation of alkali rich carbonates may occur. The temperature at which condensation begins is mainly depending on the amount of potassium present; the condensation temperature increases with increasing potassium content. In the first experimental work

  13. Ionic and electronic transport across interfaces in thin electrolyte film, anode supported solid oxide fuel cells

    Science.gov (United States)

    Lim, Hyung-Tae

    In transport studies in oxygen ion conductors, oxygen chemical potential (muO2) has been usually assumed to be equilibrated across gas/solid electrolyte interfaces. However, since the interfaces exhibit different properties from the bulk, they must have their own ionic and electronic properties. In this study, Pt reference electrodes were embedded within the electrolyte (gadolinia-doped ceria; GDC) in an anode-supported solid oxide fuel cell to measure the electrochemical potential of electrons (ϕ) through the bulk electrolyte and its interfaces under fuel cell operating condition. Based on local equilibrium assumption, which leads to relations between electrochemical potentials of charged species and chemical potential of neutral species, the corresponding mu O2 was estimated. When the GDC is protected by a thin layer of a predominantly ionic conductor from reducing atmosphere, the muO2 varied monotonically through the GDC layer, exhibiting a relatively small change across the cathode interface region. By contrast, when the GDC was exposed to hydrogen, it was significantly reduced, resulting in higher electron concentration. The corresponding mu O2 was small through the GDC layer, exhibiting an abrupt change across the cathode interface region. This difference in the muO2 variation depending upon the relative electronic conduction in the electrolyte resulted in a large difference in the cathode overpotential. The direction of ionic/electronic current and the corresponding internal muO2 through the electrolyte can have a profound effect on its stability. If cell imbalance exists in a series-connected fuel cell stack, a "bad" cell characterized by a higher resistance can be operated under a negative voltage. To investigate the SOFC stack failure by simulating abnormal behavior in a single cell test, yttira stabilized zirconia (YSZ) electrolyte cells were tested with an applied DC bias. When operating under a negative voltage, rapid degradation occurred

  14. Experimental Investigation of Two Modified Chemicallooping Compustion Cycles Using Syngas from Cylindersand the Gasification of Solid Fuels

    Science.gov (United States)

    Müller, C. R.; Brown, T. A.; Bohn, C. D.; Chuang, S. Y.; Cleeton, J. P. E.; Scott, S. A.; Dennis, J. S.

    Two modified Chemical Looping Combustion (CLC) schemes were investigated: (a) CLC with in situ gasification of a solid carbonaceous fuel in the fuel reactor, and (b) CLC for the production of high purity hydrogen from low grade syngas. A comparison between the performance of the two modified cycles using (i) syngas from cylinders and (ii) syngas derived from the gasification of various solid fuels was made. Preliminary results indicate that both processes can be operated with sufficient conversions using low and high-rank coals. However, agglomeration of the oxygen carrier was observed if wood was used in process (a), probably owing to the formation of low-melting eutectics between the oxygen carrier and metals from the wood ash.

  15. Hierarchical Load Tracking Control of a Grid-connected Solid Oxide Fuel Cell for Maximum Electrical Efficiency Operation

    DEFF Research Database (Denmark)

    Li, Yonghui; Wu, Qiuwei; Zhu, Haiyu

    2015-01-01

    Based on the benchmark solid oxide fuel cell (SOFC) dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP) optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject to the const......Based on the benchmark solid oxide fuel cell (SOFC) dynamic model for power system studies and the analysis of the SOFC operating conditions, the nonlinear programming (NLP) optimization method was used to determine the maximum electrical efficiency of the grid-connected SOFC subject...... to the constraints of fuel utilization factor, stack temperature and output active power. The optimal operating conditions of the grid-connected SOFC were obtained by solving the NLP problem considering the power consumed by the air compressor. With the optimal operating conditions of the SOFC for the maximum...

  16. Epidemiological evidence that indoor air pollution from cooking with solid fuels accelerates skin aging in Chinese women.

    Science.gov (United States)

    Li, Miaozhu; Vierkötter, Andrea; Schikowski, Tamara; Hüls, Anke; Ding, Anan; Matsui, Mary S; Deng, Binwei; Ma, Chuan; Ren, Aiguo; Zhang, Juan; Tan, Jingze; Yang, Yajun; Jin, Li; Krutmann, Jean; Li, Zhiwen; Wang, Sijia

    2015-08-01

    Recently, we showed that outdoor air pollution exposure from traffic and industry is associated with an increased risk of skin aging in Caucasian women. In China, indoor air pollution exposure caused by the use of solid fuels like coal is a major health problem and might also increase the risk of skin aging in Chinese women. As cooking with solid fuels is a major source of indoor air pollution exposure in China, we aimed to test if cooking with solid fuels is associated with more pronounced skin aging in Chinese women. We conducted two cross-sectional studies in China to assess the association between cooking with solid fuels and signs of skin aging. In Pingding (in northern China) we assessed N=405 and in Taizhou (in southern China) N=857 women between 30 and 90 years of age. Skin aging was evaluated by the SCINEXA score. Indoor air pollution exposure, sun exposure, smoking and other confounders were assessed by questionnaires. Associations were then tested by linear and logistic regression analyses adjusted for further confounders. The analysis showed that cooking with solid fuels was significantly associated with a 5-8% more severe wrinkle appearance on face and an 74% increased risk of having fine wrinkles on back of hands in both studies combined, independent of age and other influences on skin aging. The present studies thus corroborate our previous finding that air pollution is associated with skin aging and extend it by showing that indoor air pollution might be another risk factor for skin aging. Copyright © 2015. Published by Elsevier Ireland Ltd.

  17. Experimental investigation of the ignition and flammability limits of various hydrocarbon fuels in a two-dimensional solid-fuel ramjet. Master's thesis

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, R.C.

    1987-06-01

    An experimental investigation was conducted to study the effects of inlet step height on ignition and flammability limits and recirculation-zone and boundary-layer combustion phenomena of various hydrocarbon fuels. A windowed two-dimensional solid-fuel ramjet (SFRJ) was utilized. Hydrocarbon fuels were burned under conditions similar to the actual flight were studied using a variable geometry inlet, an automatic data acquisition system, and high speed motion pictures of the interior of the combustion chamber at the recirculation zone and the boundary layer development region. Data was obtained at a mass flux of 0.2 1bm/in2-sec at a nominal air inlet temperature of 1000 R with pressures ranging from 100 to 150 psia.

  18. Comparison of the Characteristics of Solid Type and Annular Type Nuclear Fuels Using Thermoelastic-Plastic-Creep FEM

    Directory of Open Access Journals (Sweden)

    Young-Doo Kwon

    2016-01-01

    Full Text Available The purpose of this study is to compare the characteristics of two types of nuclear fuel using the finite element program of thermoelastic-plastic-creep analysis. The analyzed fuel rods are of two types, solid and annular ones, and their thermomechanical characteristics are compared. Thermoelastic-plastic-creep analyses were made using an in-house finite element analysis program that adopts the “effective-stress-function” algorithm. The temperature-dependent material properties, which were obtained from the experiments for actual nuclear reactors, are adopted. The effects of type of fuel systems are revealed in both stresses and temperature distributions. The maximum tensile and compressive hoop stress of pellet and cladding are monitored to evaluate the mechanical behavior, and the maximum temperature is used to evaluate the thermal behavior. Although the annular type of fuel has certain disadvantage, it would be used very effectively or safely in future nuclear power plants.

  19. A performance analysis of integrated solid oxide fuel cell and heat recovery steam generator for IGFC system

    DEFF Research Database (Denmark)

    Rudra, Souman; Lee, Jinwook; Rosendahl, Lasse

    2010-01-01

    Solid oxide fuel cell (SOFC) is a promising technology for electricity generation. Sulfur-free syngas from a gas-cleaning unit serves as fuel for SOFC in integrated gasification fuel cell (IGFC) power plants. It converts the chemical energy of fuel gas directly into electric energy, thus high...... efficiencies can be achieved. The outputs from SOFC can be utilized by heat recovery steam generator (HRSG), which drives the steam turbine for electricity production. The SOFC stack model was developed using the process flow sheet simulator Aspen Plus, which is of the equilibrium type. Various ranges...... describes IGFC power plants, particularly the optimization of HRSG to improve the efficiency of the heat recovery from the SOFC exhaust gas and to maximize the power production in the steam cycle in the IGFC system. HRSG output from different pressure levels varies depending on the SOFC output. The steam...

  20. Synthesis, characterization and electrical properties of solid electrolyte for solid oxide fuel cell; Preparacao, caracterizacao e propriedades eletricas de eletrolito solido para celula a combustivel de oxido solido

    Energy Technology Data Exchange (ETDEWEB)

    Berton, Marco Antonio Coelho; Garcia, Carlos Mario; Matos, Jeferson Hrenechen [Instituto de Tecnologia para o Desenvolvimento (LACTEC), Curitiba, PR (Brazil)], Emails: felsky@latec.org.br, garcia@latec.org.br, jeferson.h@latec.org.br

    2010-04-15

    Solid electrolytes of BaCe{sub 08}Gd{sub O29} were prepared by the polymeric precursor method. X-ray diffraction data shows a single phase with orthorhombic crystalline structure. The densification process was followed by scanning electronic microscopy and apparent density measurements. The apparent density was developed for different temperatures of sintering, reaching > 96% for sintered temperature of 1550 {sup 0}C deg . The electrochemical impedance analysis was development in the temperature of 400-700 deg C, in air atmosphere at 700 deg C a value of 30,6 mS.cm{sup -1} was obtained. The results of conductivity have confirmed the gadolinium doped barium cerate has a great potential for use as solid electrolyte for intermediate temperature solid oxide fuel cell, at experimental controlled conditions. (author)

  1. Contributions from transport, solid fuel burning and cooking to primary organic aerosols in two UK cities

    Directory of Open Access Journals (Sweden)

    J. D. Allan

    2010-01-01

    Full Text Available Organic matter frequently represents the single largest fraction of fine particulates in urban environments and yet the exact contributions from different sources and processes remain uncertain, owing in part to its substantial chemical complexity. Positive Matrix Factorisation (PMF has recently proved to be a powerful tool for the purposes of source attribution and profiling when applied to ambient organic aerosol data from the Aerodyne Aerosol Mass Spectrometer (AMS. Here we present PMF analysis applied to AMS data from UK cities for the first time. Three datasets are analysed, with the focus on objectivity and consistency. The data were collected in London during the Regent's Park and Tower Environmental Experiment (REPARTEE intensives and Manchester. These occurred during the autumn and wintertime, such that the primary fraction would be prominent. Ambiguities associated with rotationality within sets of potential solutions are explored and the most appropriate solution sets selected based on comparisons with external data. In addition to secondary organic aerosols, three candidate sources of primary organic aerosol (POA were identified according to mass spectral and diurnal profiles; traffic emissions, cooking and solid fuel burning (for space heating. Traffic represented, on average, 40% of POA during colder conditions and exhibited a hydrocarbon-like mass spectrum similar to those previously reported. Cooking aerosols represented 34% of POA and through laboratory work, their profile was matched with that sampled from the heating of seed oils, rather than previously-published spectra derived from charbroiling. This suggests that in these locations, oil from frying may have contributed more to the particulate than the meat itself. Solid fuel aerosols represented 26% of POA during cold weather conditions but were not discernable during the first REPARTEE campaign, when conditions were warmer than the other campaigns. This factor showed

  2. Lanthanum chromite materials as potential symmetrical electrodes for Solid Oxide Fuel Cells

    Directory of Open Access Journals (Sweden)

    Ruiz-Morales, J. C.

    2007-08-01

    Full Text Available A commonly used interconnector material has been tested as electrode for a new concept of Solid Oxide Fuel Cell, where the same material could be used, simultaneously, as interconnector, anode and cathode. We have found that a typical substituted chromite, such as La0.7Ca0.3CrO3-δ (LCC can be considered a good candidate for such configuration, due to its high electronic conductivity in both reducing and oxidising conditions, and moderate catalytic properties for oxygen reduction and hydrogen oxidation. The symmetrical design renders performances of 100 mWcm-2 at 950ºC, using O2 and H2 as oxidant and fuel respectively. Performances exceeding 300 mWcm-2 can be predicted for a 100μm-thick YSZ electrolyte.

    Un material comúnmente utilizado como interconector ha sido probado como electrodo para un nuevo concepto de Pila de Combustible de Óxidos Sólido, en el cual el mismo material se utiliza, simultáneamente, como interconector, ánodo y cátodo. Hemos encontrado que una cromita típica como La0.7Ca0.3CrO3-δ (LCC puede ser considerada una buena candidata para dicha configuración, debido a sus altas conductividades eléctricas tanto en condiciones reductoras como oxidantes y una aceptable actividad catalítica para la reducción del oxígeno y la oxidación del hidrógeno. El diseño simétrico permite obtener rendimientos del orden de 100mWcm-2 a 950ºC, utilizando O2 e H2 como oxidante y combustible, respectivamente. Rendimientos que superan los 300mWcm-2 pueden predecirse para pilas con electrolitos de YSZ de 100 μm de grosor.

  3. Intermediate temperature solid oxide fuel cell based on lanthanum gallate electrolyte

    Science.gov (United States)

    Inagaki, Toru; Nishiwaki, Futoshi; Yamasaki, Satoru; Akbay, Taner; Hosoi, Kei

    The Kansai Electric Power Co. Inc. (KEPCO) and Mitsubishi Materials Corporation (MMC) have been developing intermediate temperature solid oxide fuel cells (IT-SOFCs) which are operable at a temperature range between 600 and 800 °C. There are some significant features in IT-SOFC of KEPCO-MMC: (1) highly conductive lanthanum gallate-based oxide is adopted as an electrolyte to realize high-performance disk-type electrolyte-supported cells; (2) the cell-stacks with seal-less structure using metallic separators allow residual fuel to burn around the stack and the combustion heat is utilized for thermally self-sustainable operation; (3) the separators have flexible arms by which separate compressive forces can be applied for manifold parts and interconnection parts. We are currently participating in the project by New Energy and Industrial Technology Development Organization (NEDO) to develop 10 kW-class combined heat and power (CHP) systems. In FY2006, a 10 kW-class module was developed, with which the electrical efficiency of 50%HHV was obtained based on DC 12.6 kW. In the first quarter of FY2007, the 10 kW-class CHP system using the module gave the electrical efficiency of 41%HHV on AC 10 kW and the overall efficiency of 82%HHV when exhaust heat was recovered as 60 °C hot water. Currently, the operation has been accumulated for about 2500 h to evaluate the long-term stability of the system.

  4. Finial Scientific/Technical Report: Application of a Circulating Fluidized Bed Process for the Chemical Looping Combustion of Solid Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Wei-Ping Pan; Dr. John T. Riley

    2005-10-10

    Chemical Looping Combustion is a novel combustion technology for the inherent separation of the greenhouse gas, CO{sub 2}. In 1983, Richter and Knoche proposed reversible combustion, which utilized both the oxidation and reduction of metal. Metal associated with its oxidized form as an oxygen carrier was circulated between two reactors--oxidizer and reducer. In the reducer, the solid oxygen carrier reacts with the fuel to produce CO{sub 2}, H{sub 2}O and elemental metal only. Pure CO{sub 2} will be obtained in the exit gas stream from the reducer after H{sub 2}O is condensed. The pure CO{sub 2} is ready for subsequent sequestration. In the oxidizer, the elemental metal reacts with air to form metal oxide and separate oxygen from nitrogen. Only nitrogen and some unused oxygen are emitted from the oxidizer. The advantage of CLC compared to normal combustion is that CO{sub 2} is not diluted with nitrogen but obtained in a relatively pure form without any energy needed for separation. In addition to the energy-free purification of CO{sub 2}, the CLC process also provides two other benefits. First, NO{sub x} formation can be largely eliminated. Secondly, the thermal efficiency of a CLC system is very high. Presently, the CLC process has only been used with natural gas. An oxygen carrier based on an energy balance analysis and thermodynamics analysis was selected. Copper (Cu) seems to be the best choice for the CLC system for solid fuels. From this project, the mechanisms of CuO reduction by solid fuels may be as follows: (1) If pyrolysis products of solid fuels are available, reduction of CuO could start at about 400 C or less. (2) If pyrolysis products of solid fuels are unavailable and the reduction temperature is lower, reduction of CuO could occur at an onset temperature of about 500 C, char gasification reactivity in CO{sub 2} was lower at lower temperatures. (3) If pyrolysis products of solid fuels are unavailable and the reduction temperature is higher than 750 C

  5. Low Temperature Constrained Sintering of Cerium Gadolinium OxideFilms for Solid Oxide Fuel Cell Applications

    Energy Technology Data Exchange (ETDEWEB)

    Nicholas, Jason Dale [Univ. of California, Berkeley, CA (United States)

    2007-01-01

    Cerium gadolinium oxide (CGO) has been identified as an acceptable solid oxide fuel cell (SOFC) electrolyte at temperatures (500-700 C) where cheap, rigid, stainless steel interconnect substrates can be used. Unfortunately, both the high sintering temperature of pure CGO, >1200 C, and the fact that constraint during sintering often results in cracked, low density ceramic films, have complicated development of metal supported CGO SOFCs. The aim of this work was to find new sintering aids for Ce0.9Gd0.1O1.95, and to evaluate whether they could be used to produce dense, constrained Ce0.9Gd0.1O1.95 films at temperatures below 1000 C. To find the optimal sintering aid, Ce0.9Gd0.1O1.95 was doped with a variety of elements, of which lithium was found to be the most effective. Dilatometric studies indicated that by doping CGO with 3mol% lithium nitrate, it was possible to sinter pellets to a relative density of 98.5% at 800 C--a full one hundred degrees below the previous low temperature sintering record for CGO. Further, it was also found that a sintering aid's effectiveness could be explained in terms of its size, charge and high temperature mobility. A closer examination of lithium doped Ce0.9Gd0.1O1.95 indicated that lithium affects sintering by producing a Li2O-Gd2O3-CeO2 liquid at the CGO grain boundaries. Due to this liquid phase sintering, it was possible to produce dense, crack-free constrained films of CGO at the record low temperature of 950 C using cheap, colloidal spray deposition processes. This is the first time dense constrained CGO films have been produced below 1000 C and could help commercialize metal supported ceria based solid oxide fuel cells.

  6. Oxygen transport in perovskite-type solid oxide fuel cell materials: insights from quantum mechanics.

    Science.gov (United States)

    Muñoz-García, Ana B; Ritzmann, Andrew M; Pavone, Michele; Keith, John A; Carter, Emily A

    2014-11-18

    CONSPECTUS: Global advances in industrialization are precipitating increasingly rapid consumption of fossil fuel resources and heightened levels of atmospheric CO2. World sustainability requires viable sources of renewable energy and its efficient use. First-principles quantum mechanics (QM) studies can help guide developments in energy technologies by characterizing complex material properties and predicting reaction mechanisms at the atomic scale. QM can provide unbiased, qualitative guidelines for experimentally tailoring materials for energy applications. This Account primarily reviews our recent QM studies of electrode materials for solid oxide fuel cells (SOFCs), a promising technology for clean, efficient power generation. SOFCs presently must operate at very high temperatures to allow transport of oxygen ions and electrons through solid-state electrolytes and electrodes. High temperatures, however, engender slow startup times and accelerate material degradation. SOFC technologies need cathode and anode materials that function well at lower temperatures, which have been realized with mixed ion-electron conductor (MIEC) materials. Unfortunately, the complexity of MIECs has inhibited the rational tailoring of improved SOFC materials. Here, we gather theoretically obtained insights into oxygen ion conductivity in two classes of perovskite-type materials for SOFC applications: the conventional La1-xSrxMO3 family (M = Cr, Mn, Fe, Co) and the new, promising class of Sr2Fe2-xMoxO6 materials. Using density functional theory + U (DFT+U) with U-J values obtained from ab initio theory, we have characterized the accompanying electronic structures for the two processes that govern ionic diffusion in these materials: (i) oxygen vacancy formation and (ii) vacancy-mediated oxygen migration. We show how the corresponding macroscopic oxygen diffusion coefficient can be accurately obtained in terms of microscopic quantities calculated with first-principles QM. We find that the

  7. Modeling and experimental validation of CO heterogeneous chemistry and electrochemistry in solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Yurkiv, Vitaly

    2010-12-17

    In the present work experimental and numerical modeling studies of the heterogeneously catalyzed and electrochemical oxidation of CO at Nickel/yttria-stabilized zirconia (YSZ) solid oxide fuel cell (SOFC) anode systems were performed to evaluate elementary charge-transfer reaction mechanisms taking place at the three-phase boundary of CO/CO{sub 2} gas-phase, Ni electrode, and YSZ electrolyte. Temperature-programmed desorption and reaction experiments along with density functional theory calculations were performed to determine adsorption/desorption and surface diffusion kinetics as well as thermodynamic data for the CO/CO{sub 2}/Ni and CO/CO{sub 2}/YSZ systems. Based on these data elementary reaction based models with four different charge transfer mechanisms for the electrochemical CO oxidation were developed and applied in numerical simulations of literature experimental electrochemical data such as polarization curves and impedance spectra. Comparison between simulation and experiment demonstrated that only one of the four charge transfer mechanisms can consistently reproduce the electrochemical data over a wide range of operating temperatures and CO/CO{sub 2} gas compositions. (orig.) [German] In der vorliegenden Arbeit wurden experimentelle und numerische Untersuchungen zur heterogen katalysierten und elektrochemischen Oxidation von CO an Anodensystemen (bestehend aus Nickel und yttriumdotiertem Zirkoniumdioxid, YSZ) von Festoxidbrennstoffzellen (engl. Solid Oxide Fuel Cells, SOFCs) ausgefuehrt, um den mikroskopischen Mechanismus der an der CO/CO{sub 2}-Gasphase/Ni-Elektrode/YSZ-Elektrolyt- Dreiphasen-Grenzflaeche ablaufenden Ladungsuebertragungsreaktion aufzuklaeren. Temperaturprogrammierte Desorptionsmessungen (TPD) und Temperaturprogrammierte Reaktionsmessungen (TPR) sowie Dichtefunktionaltheorierechnungen wurden ausgefuehrt, um adsorptions-, desorptions- und reaktionskinetische sowie thermodynamische Daten fuer die CO/CO{sub 2}/Ni- und CO/CO{sub 2}/YSZ

  8. New Experimental Characterisation Methods for Solid Biomass Fuels to be used in Combined Heat and Power Generation

    Energy Technology Data Exchange (ETDEWEB)

    Gunnar Eriksson, (Energy Engineering Div., Luleaa Univ. of Technology, S-971 87 Luleaa (Sweden)); Nordgren, Daniel; Berg, Magnus (Vattenfall Research and Development AB, S-814 26 Aelvkarleby (Sweden))

    2008-10-15

    The replacement of fossil fuels will lead to an increasing demand for unconventional biofuels. Fuel characterisation to predict combustion properties and facilitate the choice of combustion applications is important to avoid costly and time-consuming mistakes. Traditional methods are developed mainly for coal. Therefore procedures adapted specifically for solid biomass fuels are needed. This work is a survey on approaches for combustion characterisation of biomass developed during the last ten years. Innovative characterisation methods of interest concern: 1) Fuel handling behaviour: grindablility, erosion and abrasion properties. 2) Combustion characterisation: devolatilisation properties (important for ignition and flame stability), char burnout time. 3) Slagging and fouling properties of ash: ash particle formation, ash particle size distribution, ash composition, melting and gasification temperatures, slagging of bottom ash, reducing the risk by mixing with other fuels or using fuel additives and choice of suitable combustion applications for specific fuels. The main conclusions are: 1) a method to measure grindability which takes electric power consumption into account is needed as the Hardgrove Grindability Index used for coal grinding is pointless for biofuels, 2) there is a need to develop convenient low-cost methods to measure slagging and fouling tendencies, devolatilisation kinetics and char burnout for high heating rates found in fluidised beds and powder burners

  9. Indoor air pollution from solid biomass fuels combustion in rural agricultural area of Tibet, China

    Energy Technology Data Exchange (ETDEWEB)

    Gao, X.; Yu, Q.; Gu, Q.; Chen, Y.; Ding, K.; Zhu, J.; Chen, L.

    2009-01-15

    In this study, we are trying to investigate the indoor air pollution and to estimate the residents pollution exposure reduction of energy altering in rural Tibet. Daily PM{sub 2.5} monitoring was conducted in indoor microenvironments like kitchen, living-room, bedroom, and yard in rural Tibet from December 2006 to March 2007. For kitchen air pollution, impact of two fuel types, methane and solid biomass fuels (SBFs), were compared. Questionnaire survey on the domestic energy pattern and residents daily activity pattern was performed in Zha-nang County. Daily average PM{sub 2.5} concentrations in kitchen, living-room, bedroom, and yard were 134.91 mug/m3 (mean, n = 45, 95%CI 84.02, 185.80), 103.61 mug/m3 (mean, n = 21, 95%CI 85.77, 121.45), 76.13 mug/m3 (mean, n = 18, 95%CI 57.22, 95.04), and 78.33 mug/m3 (mean, n = 34, 95%CI 60.00, 96.65) respectively. Using SBFs in kitchen resulted in higher indoor pollution than using methane. PM{sub 2.5} concentrations in kitchen with dung cake, fuel wood and methane use were 117.41 mug/m3 (mean, n = 18, 95%CI 71.03, 163.79), 271.11 mug/m3 (mean, n = 12, 95%CI 104.74, 437.48), and 46.96 mug/m3 (mean, n = 15, 95%CI 28.10, 65.82) respectively. Family income has significant influence on cooking energy choice, while the lack of commercial energy supply affects the energy choice for heating more. The effects of two countermeasures to improve indoor air quality were estimated in this research. One is to replace SBFs by clean energy like methane, the other is to separate the cooking place from other rooms and by applying these countermeasures, residents exposure to particulate matters would reduce by 25-50% (methane) or 20-30% (separation) compared to the present situation. (au)

  10. In situ solid-state NMR spectroscopy of electrochemical cells: batteries, supercapacitors, and fuel cells.

    Science.gov (United States)

    Blanc, Frédéric; Leskes, Michal; Grey, Clare P

    2013-09-17

    Electrochemical cells, in the form of batteries (or supercapacitors) and fuel cells, are efficient devices for energy storage and conversion. These devices show considerable promise for use in portable and static devices to power electronics and various modes of transport and to produce and store electricity both locally and on the grid. For example, high power and energy density lithium-ion batteries are being developed for use in hybrid electric vehicles where they improve the efficiency of fuel use and help to reduce greenhouse gas emissions. To gain insight into the chemical reactions involving the multiple components (electrodes, electrolytes, interfaces) in the electrochemical cells and to determine how cells operate and how they fail, researchers ideally should employ techniques that allow real-time characterization of the behavior of the cells under operating conditions. This Account reviews the recent use of in situ solid-state NMR spectroscopy, a technique that probes local structure and dynamics, to study these devices. In situ NMR studies of lithium-ion batteries are performed on the entire battery, by using a coin cell design, a flat sealed plastic bag, or a cylindrical cell. The battery is placed inside the NMR coil, leads are connected to a potentiostat, and the NMR spectra are recorded as a function of state of charge. (7)Li is used for many of these experiments because of its high sensitivity, straightforward spectral interpretation, and relevance to these devices. For example, (7)Li spectroscopy was used to detect intermediates formed during electrochemical cycling such as LixC and LiySiz species in batteries with carbon and silicon anodes, respectively. It was also used to observe and quantify the formation and growth of metallic lithium microstructures, which can cause short circuits and battery failure. This approach can be utilized to identify conditions that promote dendrite formation and whether different electrolytes and additives can help

  11. 17{sup th} symposium bio energy. Solid fuels, biofuels, biogas; 17. Symposium Bioenergie. Festbrennstoffe, Biokraftstoffe, Biogas

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-07-01

    Within the 17th symposium of the OTTI e.V. from 20th to 21st November, 2008 in Bad Staffelstein, the following lectures were held: (1) Development, state of the art and future of bioenergy in Germany and Europe; (2) Safe power supply by means of bio-energy ; (3) Is the course set right for the future?; (4) Survey lecture on filter technology; (5) Emissions of fine dust from small wood firings - Actual results of research (P. Turowski); (6) Particle separator for fine dust at wood and pellet firings; (7) International trade of solid biomass - Aspects of sustainability and other restrictions; (8) The PELLETS rate at LAS project - A comprehensive survey on the European pellet market; (9) Energetic potentials of renewable raw materials (rapeseed, short-rotation wood) and high-wood content residues from the landscape conservation in Baden-Wuerttemberg; (10) Biomass-Combined-Cycle: Pilot plant produces 120 kW electricity from 400 kW wood fire - The second year of te project; (11) Minimization of emissions of fine dust, CO and NO{sub x} from small heating plants; (12) Climate protection from cost factor to assets for companies; (13) Aspects of pelletizing trunk wood; (14) Flow of wood in the cluster forestry and timber in Bavaria; (15) Biomass sustainability regulation; (16) Energy balances and life cycle assessment of the sustainable production of ethanol from raw materials containing starch and cellulose; (17) Decentralized/regional energy concepts using rapeseed fuel as an example; (18) Shortage of crude oil and biofuels - On the criteria of forward-looking biogenic fuels; (19) Bioethanol for decentralized cogeneration - Technical aspects in the InnoNet project regenerative central heating system; (20) Impact of the production process winter rape and the process of oil extraction on the quality of raw materials and on the economy of rapeseed fuels; (21) Investigation of the physico-chemical properties of Jatropha oil as a basis for the mapping of vegetable landscape

  12. Dynamic modeling and predictive control in solid oxide fuel cells first principle and data-based approaches

    CERN Document Server

    Huang, Biao; Murshed, A K M Monjur

    2012-01-01

    The high temperature solid oxide fuel cell (SOFC) is identified as one of the leading fuel cell technology contenders to capture the energy market in years to come. However, in order to operate as an efficient energy generating system, the SOFC requires an appropriate control system which in turn requires a detailed modelling of process dynamics. Introducting state-of-the-art dynamic modelling, estimation, and control of SOFC systems, this book presents original modelling methods and brand new results as developed by the authors. With comprehensive coverage and bringing together many

  13. Performance Comparison on Repowering of a Steam Power Plant with Gas Turbines and Solid Oxide Fuel Cells

    DEFF Research Database (Denmark)

    Rokni, Masoud

    2016-01-01

    into an existing steam cycle which was built decades ago. Thus, traditional repowering results in combined cycles (CC). High temperature fuel cells (such as solid oxide fuel cell (SOFC)) could also be used as a topping cycle, achieving even higher global plant efficiency and even lower specific CO2 emissions....... Decreasing the operating temperature in a SOFC allows the use of less complex materials and construction methods, consequently reducing plant and the electricity costs. A lower working temperature makes it also suitable for topping an existing steam cycle, instead of gas turbines. This is also the target...

  14. Single-chamber solid oxide fuel cell technology - From its origins to today's state of the art

    Energy Technology Data Exchange (ETDEWEB)

    Khun, M. [Department of Mechanical Engineering, Ecole Polytechnique de Montreal, Montreal, Quebec, H3T 1J4 (Canada); Napporn, T. W. [Equipe Electrocatalyse, Laboratoire de Catalyse en Chimie Organique, UMR CNRS 6503, Universite de Poitiers, Poitiers (France)

    2010-07-01

    In single-chamber solid oxide fuel cells (SC-SOFCs), both anode and cathode are situated in a common gas chamber and are exposed to a mixture of fuel and oxidant. The working principle is based on the difference in catalytic activity of the electrodes for the respective anodic and cathodic reactions. The resulting difference in oxygen partial pressure between the electrodes leads to the generation of an open circuit voltage. Progress in SC-SOFC technology has enabled the generation of power outputs comparable to those of conventional SOFCs. This paper provides a detailed review of the development of SC-SOFC technology. (author)

  15. Energy efficient refuse derived fuel (RDF from municipal solid waste rejects: a case for Coimbatore

    Directory of Open Access Journals (Sweden)

    Offor N Kimambo

    2014-05-01

    Full Text Available In this paper production of energy efficient Refuse Derived Fuel (RDF from municipal solid waste rejects was carried out during August 2012 – April 2013 in Coimbatore City India. Municipal Solid wastes rejects (paper, plastics with exception of polyvinyl chloride, textiles were collected from waste dump yard of Coimbatore City. Sawdust, coir dust, water hyacinth and rice husk were mixed with the collected wastes at a fixed amount of 20 percent. After grinding, cassava starch was used as a binder to produce RDF briquettes with the help of uniaxial piston briquettes making machine. Physical, chemical and thermal characteristics of the RDF were studied to assess their potential use as energy efficient material. The analyses were divided into three categories namely, physical, proximate and ultimate analyses. Results indicated that, under physical and proximate analyses; impact resistance index (IRI for all the RDF samples were 200, density were less than 1 kg cm-3, moisture were less than 10 % wt, ash content varied from 2.8 to 9.2 % wt, whilst volatile mater had mean value of 83.1 % wt and fixed carbon which is by subtraction ranged from 1.4 to 9.2 % wt. With respect to Ultimate analysis, Oxygen, carbon, hydrogen varied from 27.01 to 39.78 % wt, 44.8 to59.7 % wt, 5.9 to 8.1 % wt respectively. On the other hand nitrogen, sulfur and chlorine ranged from 0.18 to 0.87 % wt, 0.27 to 0.71 % wt and 0.339 to0.521 % wt respectively. Calorific values (high heating values ranged from 5085 to 6474.9 kcal kg-1. The results were compared with Energy research Centre for the Netherland database and noted that with exception to moisture, fixed carbon and hydrogen other parameters had a significant lower or higher differences. From the study, RDF from municipal solid wastes rejects along with the additives produced high energy efficient materials. DOI: http://dx.doi.org/10.3126/ije.v3i2.10530 International Journal of the Environment Vol.3(2 2014: 205-215

  16. Surface strontium enrichment on highly active perovskites for oxygen electrocatalysis in solid oxide fuel cells

    KAUST Repository

    Crumlin, Ethan J.

    2012-01-01

    Perovskite oxides have high catalytic activities for oxygen electrocatalysis competitive to platinum at elevated temperatures. However, little is known about the oxide surface chemistry that influences the activity near ambient oxygen partial pressures, which hampers the design of highly active catalysts for many clean-energy technologies such as solid oxide fuel cells. Using in situ synchrotron-based, ambient pressure X-ray photoelectron spectroscopy to study the surface chemistry changes, we show that the coverage of surface secondary phases on a (001)-oriented La 0.8Sr 0.2CoO 3-δ (LSC) film becomes smaller than that on an LSC powder pellet at elevated temperatures. In addition, strontium (Sr) in the perovskite structure enriches towards the film surface in contrast to the pellet having no detectable changes with increasing temperature. We propose that the ability to reduce surface secondary phases and develop Sr-enriched perovskite surfaces of the LSC film contributes to its enhanced activity for O 2 electrocatalysis relative to LSC powder-based electrodes. © 2012 The Royal Society of Chemistry.

  17. Energy analysis of a trigeneration plant based on solid oxide fuel cell and organic Rankine cycle

    Energy Technology Data Exchange (ETDEWEB)

    Al-Sulaiman, Fahad A. [Mechanical and Aerospace Engineering Department, Carleton University, 1125 Colonel By Drive, Ottawa, Ontario (Canada); Dincer, Ibrahim [Faculty of Engineering and Applied Science, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, Ontario (Canada); Hamdullahpur, Feridun [Mechanical and Mechatronics Engineering Department, University of Waterloo, 200 University Avenue West, Waterloo, Ontario (Canada)

    2010-05-15

    In this study, energy analysis of a trigeneration plant based on solid oxide fuel cell (SOFC) and organic Rankine cycle (ORC) is conducted. The physical and thermodynamic elements of the plant include an SOFC, an ORC, a heat exchanger for the heating process and a single-effect absorption chiller for cooling. The results obtained from this study show that there is at least a 22% gain in efficiency using the trigeneration plant compared with the power cycle (SOFC and ORC). The study also shows that the maximum efficiency of the trigeneration plant is 74%, heating cogeneration is 71%, cooling cogeneration is 57% and net electricity is 46%. Furthermore, it is found that the highest net power output that can be provided by the trigeneration plant considered in this study is 540 kW and, the highest SOFC-AC power is 520 kW. The study reveals that the inlet pressure of the turbine has an insignificant effect on the efficiency. The study also examines the effect of both the SOFC current density and the SOFC inlet flow temperature on the cell voltage and voltage loss. (author)

  18. Percolation Theory in Solid Oxide Fuel Cell Composite Electrodes with a Mixed Electronic and Ionic Conductor

    Directory of Open Access Journals (Sweden)

    Meng Ni

    2013-03-01

    Full Text Available Percolation theory is generalized to predict the effective properties of specific solid oxide fuel cell composite electrodes, which consist of a pure ion conducting material (e.g., YSZ or GDC and a mixed electron and ion conducting material (e.g., LSCF, LSCM or CeO2. The investigated properties include the probabilities of an LSCF particle belonging to the electron and ion conducting paths, percolated three-phase-boundary electrochemical reaction sites, which are based on different assumptions, the exposed LSCF surface electrochemical reaction sites and the revised expressions for the inter-particle ionic conductivities among LSCF and YSZ materials. The effects of the microstructure parameters, such as the volume fraction of the LSCF material, the particle size distributions of both the LSCF and YSZ materials (i.e., the mean particle radii and the non-dimensional standard deviations, which represent the particle size distributions and the porosity are studied. Finally, all of the calculated results are presented in non-dimensional forms to provide generality for practical application. Based on these results, the relevant properties can be easily evaluated, and the microstructure parameters and intrinsic properties of each material are specified.

  19. Mesoporous NiO-samaria doped ceria for low-temperature solid oxide fuel cells.

    Science.gov (United States)

    Kim, Jin-Yeop; Kim, Ji Hyeon; Choi, Hyung Wook; Kim, Kyung Hwan; Park, Sang Joon

    2014-08-01

    In order to prepare anode material for low-temperature solid oxide fuel cells (SOFCs), the mesoporous NiO-SDC was synthesized using a cationic surfactant (cetyltrimethyl-ammonium bromide; CTAB) for obtaining wide triple-phase boundary (TPB). In addition, Ni-SDC anode-supported SOFC single cells with YSZ electrolyte and LSM cathode were fabricated and the performance of single cells was evaluated at 600 °C. The microstructure of NiO-SDC was characterized by XRD, EDX, SEM, and BET, and the results showed that the mesoporous NiO-SDC with 10 nm pores could be obtained. It was found that the surface area and the electrical performance were strongly influenced by the Ni content in Ni-SDC cermets. After calcined at 600 °C, the surface area of NiO-SDC was between 90-117 m2/g at 35-45 Ni wt%, which was sufficiently high for providing large TPB in SOFC anode. The optimum Ni content for cell performance was around 45 wt% and the corresponding MPD was 0.36 W/cm2. Indeed, the mesoporous NiO-SDC cermet may be of interest for use as an anode for low-temperature SOFCs.

  20. Durability of symmetric-structured metal-supported solid oxide fuel cells

    Science.gov (United States)

    Tucker, Michael C.

    2017-11-01

    Symmetric-structure metal-supported solid oxide fuel cells (MS-SOFC) with YSZ electrolyte are fabricated with porous YSZ backbone electrodes, stainless steel supports, and infiltrated catalysts on both anode and cathode side. Durability towards aggressive thermal and redox cycling, and long-term operation is assessed. Many sealing material candidates are screened for compatibility with the cell materials and operating conditions, and a commercial sealing glass, GM31107, is selected. LSM/SDCN cells are then subjected to 200 very fast thermal cycles and 20 complete redox cycles, with minimal impact to cell performance. LSM/SDCN and SDCN/SDCN cells are operated for more than 1200 h at 700 °C. The seal and cell hermeticity is maintained, and cell ohmic impedance does not change significantly during operation. Electrode polarization increases during operation, leading to significant degradation of the cell performance. In-operando EIS and post-mortem SEM/EDS analysis suggest that catalyst coarsening and cathode Cr deposition are the dominant degradation modes.