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Sample records for reforming carbonate fuel

  1. Nickel catalysts for internal reforming in molten carbonate fuel cells

    NARCIS (Netherlands)

    Berger, R.J.; Berger, R.J.; Doesburg, E.B.M.; Doesburg, E.B.M.; van Ommen, J.G.; Ross, J.R.H.; Ross, J.R.H.

    1996-01-01

    Natural gas may be used instead of hydrogen as fuel for the molten carbonate fuel cell (MCFC) by steam reforming the natural gas inside the MCFC, using a nickel catalyst (internal reforming). The severe conditions inside the MCFC, however, require that the catalyst has a very high stability. In

  2. Development of large scale internal reforming molten carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Sasaki, A.; Shinoki, T.; Matsumura, M. [Mitsubishi Electric Corp., Hyogo (Japan)

    1996-12-31

    Internal Reforming (IR) is a prominent scheme for Molten Carbonate Fuel Cell (MCFC) power generating systems in order to get high efficiency i.e. 55-60% as based on the Higher Heating Value (HHV) and compact configuration. The Advanced Internal Reforming (AIR) technology has been developed based on two types of the IR-MCFC technology i.e. Direct Internal Reforming (DIR) and Indirect Internal Reforming (DIR).

  3. Solar Reforming of Carbon Dioxide to Produce Diesel Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Dennis Schuetzle; Robert Schuetzle

    2010-12-31

    This project focused on the demonstration of an innovative technology, referred to as the Sunexus CO2 Solar Reformer, which utilizes waste CO2 as a feedstock for the efficient and economical production of synthetic diesel fuel using solar thermal energy as the primary energy input. The Sunexus technology employs a two stage process for the conversion of CO2 to diesel fuel. A solar reforming system, including a specially designed reactor and proprietary CO2 reforming catalyst, was developed and used to convert captured CO2 rich gas streams into syngas (primarily hydrogen and carbon monoxide) using concentrated solar energy at high conversion efficiencies. The second stage of the system (which has been demonstrated under other funding) involves the direct conversion of the syngas into synthetic diesel fuel using a proprietary catalyst (Terra) previously developed and validated by Pacific Renewable Fuels and Chemicals (PRFC). The overall system energy efficiency for conversion of CO2 to diesel fuel is 74%, due to the use of solar energy. The results herein describe modeling, design, construction, and testing of the Sunexus CO2 Solar Reformer. Extensive parametric testing of the solar reformer and candidate catalysts was conducted and chemical kinetic models were developed. Laboratory testing of the Solar Reformer was successfully completed using various gas mixtures, temperatures, and gas flow rates/space velocities to establish performance metrics which can be employed for the design of commercial plants. A variety of laboratory tests were conducted including dry reforming (CO2 and CH{sub 4}), combination dry/steam reforming (CO2, CH{sub 4} & H{sub 2}O), and tri-reforming (CO2, CH{sub 4}, H{sub 2}O & O{sub 2}). CH{sub 4} and CO2 conversions averaged 95-100% and 50-90% per reformer cycle, respectively, depending upon the temperatures and gas space velocities. No formation of carbon deposits (coking) on the catalyst was observed in any of these tests. A 16 ft. diameter

  4. Reforming performance of a plasma-catalyst hybrid converter using low carbon fuels

    International Nuclear Information System (INIS)

    Horng, R.-F.; Lai, M.-P.; Huang, H.-H.; Chang, Y.-P.

    2009-01-01

    The reforming performance of a plasma-catalyst hybrid converter using different low carbon fuels was investigated. The methodology was to use arc from spark discharge combined with an appropriate oxygen/carbon molar ratio (O 2 /C) and feeding rate of the supplied mixture. To enhance the mixing and reforming reaction, a gas intake swirl was generated by inducing the mixture tangentially into the reaction chamber. The required energy for fuel processing was provided by heat released through the oxidation of the air-fuel mixture. The reforming temperature as well as the effect of steam addition on the hydrogen production was studied. The results showed that reformate gas temperature had a profound effect on the overall reaction. The H 2 /(CO + CO 2 ) ratio reformed by both methane and propane was shown to increase with temperature and that the optimum ratio was obtained when reforming methane under 650 deg. C. The conversion efficiency of the fuel was also shown to increase with increasing temperature. The best thermal efficiency of 72.01% was obtained near 750 deg. C. The theoretical equilibrium calculations and the experimental results were compared.

  5. Modeling and parametric simulations of solid oxide fuel cells with methane carbon dioxide reforming

    International Nuclear Information System (INIS)

    Ni, Meng

    2013-01-01

    Highlights: ► A 2D model is developed for solid oxide fuel cells (SOFCs). ► CH 4 reforming by CO 2 (MCDR) is included. ► SOFC with MCDR shows comparable performance with methane steam reforming SOFC. ► Increasing CO electrochemical oxidation greatly enhances the SOFC performance. ► Effects of potential and temperature on SOFC performance are also discussed. - Abstract: A two-dimensional model is developed to simulate the performance of solid oxide fuel cells (SOFCs) fed with CO 2 and CH 4 mixture. The electrochemical oxidations of both CO and H 2 are included. Important chemical reactions are considered in the model, including methane carbon dioxide reforming (MCDR), reversible water gas shift reaction (WGSR), and methane steam reforming (MSR). It’s found that at a CH 4 /CO 2 molar ratio of 50/50, MCDR and reversible WGSR significantly influence the cell performance while MSR is negligibly small. The performance of SOFC fed with CO 2 /CH 4 mixture is comparable to SOFC running on CH 4 /H 2 O mixtures. The electric output of SOFC can be enhanced by operating the cell at a low operating potential or at a high temperature. In addition, the development of anode catalyst with high activity towards CO electrochemical oxidation is important for SOFC performance enhancement. The model can serve as a useful tool for optimization of the SOFC system running on CH 4 /CO 2 mixtures

  6. Thermodynamic analysis of carbon formation in solid oxide fuel cells with a direct internal reformer fueled by ethanol, methanol, and methane

    International Nuclear Information System (INIS)

    Laosiripojana, N.; Assabumrungrat, S.; Pavarajarn, V.; Sangtongkitcharoen, W.; Tangjitmatee, A.; Praserthdam, P.

    2004-01-01

    'Full text:' This paper concerns a detailed thermodynamic analysis of carbon formation for a Direct Internal Reformer (DIR) Solid Oxide Fuel Cells (SOFC). The modeling of DIR-SOFC fueled by ethanol, methanol, and methane were compared. Two types of fuel cell electrolytes, i.e. oxygen-conducting and hydrogen-conducting, are considered. Equilibrium calculations were performed to find the ranges of inlet steam/fuel ratio where carbon formation is thermodynamically unfavorable in the temperature range of 500-1200 K. It was found that the key parameters determining the boundary of carbon formation are temperature, type of solid electrolyte and extent of the electrochemical reaction of hydrogen. The minimum requirements of H2O/fuel ratio for each type of fuel in which the carbon formation is thermodynamically unfavored were compared. At the same operating conditions, DIR-SOFC fueled by ethanol required the lowest inlet H2O/fuel ratio in which the carbon formation is thermodynamically unfavored. The requirement decreased with increasing temperature for all three fuels. Comparison between two types of the electrolytes reveals that the hydrogen-conducting electrolyte is impractical for use, regarding to the tendency of carbon formation. This is due mainly to the water formed by the electrochemical reaction at the electrodes. (author)

  7. Non-linear model reduction and control of molten carbonate fuel cell systems with internal reforming

    Energy Technology Data Exchange (ETDEWEB)

    Sheng, Min

    2007-10-12

    Currently, the process design of fuel cells and the development of control strategies is mainly based on heuristic methods. Fuel cell models are often too complex for control purposes, or they are developed for a specific type of fuel cell and valid only in a small range of operation conditions. The application of fuel cell models to controller design is still limited. Furthermore, suitable and simple-to-implement design strategies for fuel cell control remain an open area. There is thus a motivation for simplifying dynamic models for process control applications and for designing suitable control strategies for fuel cells. This is the main objective of this work. As an application example, the 250 kW industrial molten carbonate fuel cell (MCFC) system HotModule by MTU CFC Solutions, Germany is considered. A detailed dynamic two-dimensional spatially distributed cross-flow model of a MCFC from literature is taken as a starting point for the investigation. In Chapter 2, two simplified model versions are derived by incorporating additional physical assumptions. One of the simplified models is extended to a three-dimensional stack model to deal with physical and chemical phenomena in the stack. Simulations of the stack model are performed in Chapter 3 in order to calculate the mass and temperature distributions in the direction perpendicular to the electrode area. The other simplified model forms the basis for a low order reduced model that is derived in Chapter 4. The reduced-order model is constructed by application of the Karhunen-Loeve Galerkin method. The spatial temperature, concentration and potential profiles are approximated by a set of orthogonal time independent spatial basis functions. Problem specific basis functions are generated numerically from simulation data of the detailed reference model. The advantage of this approach is that a small number of basis functions suffices in order to approximate the solution of the detailed model very well. The

  8. Characterization and Modeling of a Methanol Reforming Fuel Cell System

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart

    topologies is the Reformed Methanol Fuel Cell (RMFC) system that operates on a mix of methanol and water. The fuel is reformed with a steam reforming to a hydrogen rich gas, however with additional formation of Carbon Monoxide and Carbon Dioxide. High Temperature Polymer Electrolyte Membrane Fuel Cell (HT...... to heat up the steam reforming process. However, utilizing the excess hydrogen in the system complicates the RMFC system as the amount of hydrogen can vary depending on the fuel methanol supply, fuel cell load and the reformer gas composition. This PhD study has therefore been involved in investigating......Many fuel cells systems today are operated with compressed hydrogen which has great benefits because of the purity of the hydrogen and the relatively simple storage of the fuel. However, compressed hydrogen is stored in the range of 800 bar, which can be expensive to compress.One of the interesting...

  9. Catalytic autothermal reforming increases fuel cell flexibility

    Science.gov (United States)

    Flytzani-Stephanopoulos, M.; Voecks, G. E.

    1981-01-01

    Experimental results are presented for the autothermal reforming (ATR) of n-hexane, n-tetradecane, benzene and benzene solutions of naphthalene. The tests were run at atmospheric pressure and at moderately high reactant preheat temperatures in the 800-900 K range. Carbon formation lines were determined for paraffinic and aromatic liquids. Profiles were determined for axial bed temperature and composition. Space velocity efforts were assessed, and the locations and types of carbon were recorded. Significant reactive differences between hydrocarbons were identified. Carbon formation characteristics were hydrocarbon specific. The differing behavior of paraffinic and aromatic fuels with respect to their carbon formation may be important in explaining the narrow range of carbon-free operating conditions found in the ATR of number two fuel oil.

  10. Alkali resistant Ni-loaded yolk-shell catalysts for direct internal reforming in molten carbonate fuel cells

    Science.gov (United States)

    Jang, Won-Jun; Hong, Young Jun; Kim, Hak-Min; Shim, Jae-Oh; Roh, Hyun-Seog; Kang, Yun Chan

    2017-06-01

    A facile and scalable spray pyrolysis process is applied to synthesize multi-shelled Ni-loaded yolk-shell catalysts on various supports (Al2O3, CeO2, ZrO2, and La(OH)3). The prepared catalysts are applied to direct internal reforming (DIR) in a molten carbonate fuel cell (MCFC). Even on exposure to alkali hydroxide vapors, the Ni-loaded yolk-shell catalysts remain highly active for DIR-MCFCs. The Ni@Al2O3 microspheres show the highest conversion (92%) of CH4 and the best stability among the prepared Ni-loaded yolk-shell catalysts. Although the initial CH4 conversion of the Ni@ZrO2 microspheres is higher than that of the Ni@CeO2 microspheres, the Ni@CeO2 microspheres are more stable. The catalytic performance is strongly dependent on the surface area and acidity and also partly dependent on the reducibility. The acidic nature of Al2O3 combined with its high surface area and yolk-shell structure enhances the adsorption of CH4 and resistance against alkali poisoning, resulting in efficient DIR-MCFC reactions.

  11. On the Deposition Equilibrium of Carbon Nanotubes or Graphite in the Reforming Processes of Lower Hydrocarbon Fuels

    Directory of Open Access Journals (Sweden)

    Zdzisław Jaworski

    2017-11-01

    Full Text Available The modeling of carbon deposition from C-H-O reformates has usually employed thermodynamic data for graphite, but has rarely employed such data for impure filamentous carbon. Therefore, electrochemical data for the literature on the chemical potential of two types of purified carbon nanotubes (CNTs are included in the study. Parameter values determining the thermodynamic equilibrium of the deposition of either graphite or CNTs are computed for dry and wet reformates from natural gas and liquefied petroleum gas. The calculation results are presented as the atomic oxygen-to-carbon ratio (O/C against temperature (200 to 100 °C for various pressures (1 to 30 bar. Areas of O/C for either carbon deposition or deposition-free are computed, and indicate the critical O/C values below which the deposition can occur. Only three types of deposited carbon were found in the studied equilibrium conditions: Graphite, multi-walled CNTs, and single-walled CNTs in bundles. The temperature regions of the appearance of the thermodynamically stable forms of solid carbon are numerically determined as being independent of pressure and the analyzed reactants. The modeling indicates a significant increase in the critical O/C for the deposition of CNTs against that for graphite. The highest rise in the critical O/C, of up to 290% at 30 bar, was found for the wet reforming process.

  12. Reforming fossil fuel use : the merits, costs and risks of carbon dioxide capture and storage

    NARCIS (Netherlands)

    Damen, Kay J.

    2007-01-01

    The sense of urgency in achieving large reductions in anthropogenic CO2 emissions has increased the interest in carbon dioxide capture and storage (CCS). CCS can be defined as the separation and capture of CO2 produced at large stationary sources, followed by transport and storage in geological

  13. Multi-fuel reformers for fuel cells used in transportation. Phase 1: Multi-fuel reformers

    Science.gov (United States)

    1994-05-01

    DOE has established the goal, through the Fuel Cells in Transportation Program, of fostering the rapid development and commercialization of fuel cells as economic competitors for the internal combustion engine. Central to this goal is a safe feasible means of supplying hydrogen of the required purity to the vehicular fuel cell system. Two basic strategies are being considered: (1) on-board fuel processing whereby alternative fuels such as methanol, ethanol or natural gas stored on the vehicle undergo reformation and subsequent processing to produce hydrogen, and (2) on-board storage of pure hydrogen provided by stationary fuel processing plants. This report analyzes fuel processor technologies, types of fuel and fuel cell options for on-board reformation. As the Phase 1 of a multi-phased program to develop a prototype multi-fuel reformer system for a fuel cell powered vehicle, the objective of this program was to evaluate the feasibility of a multi-fuel reformer concept and to select a reforming technology for further development in the Phase 2 program, with the ultimate goal of integration with a DOE-designated fuel cell and vehicle configuration. The basic reformer processes examined in this study included catalytic steam reforming (SR), non-catalytic partial oxidation (POX) and catalytic partial oxidation (also known as Autothermal Reforming, or ATR). Fuels under consideration in this study included methanol, ethanol, and natural gas. A systematic evaluation of reforming technologies, fuels, and transportation fuel cell applications was conducted for the purpose of selecting a suitable multi-fuel processor for further development and demonstration in a transportation application.

  14. Hydrogen production by reforming of fossil and biomass fuels accompanied by carbon dioxide capture process is the energy source for the near future

    International Nuclear Information System (INIS)

    Aboudheir, Ahmed; Idem, Raphael; Tontiwachwuthikul, Paitoon; Wilson, Malcolm; Kambietz, Lionel

    2006-01-01

    Hydrogen has a significant future potential as an alternative energy source for the transportation sector as well as in residential homes and offices, H 2 in fuel cell power systems provides an alternative to direct fossil fuel and biomass combustion based technologies and offer the possibility for a significant reduction in greenhouse gas emission based on improved H 2 yield per unit of fossil fuel and biomass, compatibility with renewable energies and motivation to convert to a H 2 -based energy economy. Several practical techniques for H 2 production to service H 2 refuelling stations as well as homes and offices, all of which need to be located at the end of the energy distribution network, include: (1) the carbon dioxide reforming of natural gas; (2) reforming of gasoline; (3) reforming of crude ethanol. Locating the H 2 production at the end of the energy distribution network solves the well-known problems of metal fatigue and high cost of H 2 compression for long distance transportation if H 2 is produced in a large centralized plant. In addition, the ratification of the Kyoto Protocol and the need to reduce emissions of CO 2 to the atmosphere has prompted the capture and utilization of the CO 2 produced from the reforming process. In this research: (1) new efficient catalysts for each reforming process was developed; (2) a new efficient catalyst for our version of the water gas shift reaction to convert carbon monoxide to carbon dioxide was developed; (3) a new membrane separation process for production of high purity, fuel cell-grade H 2 was designed; (4) a numerical model for optimum process design and optimum utilization of resources both at the laboratory and industrial scales was developed; (5) various processes for CO 2 capture were investigated experimentally in order to achieve a net improvement in the absorption process; (6) the utilization of captured CO 2 for enhanced oil recovery and/or storage in an aging oil field were investigated; (7

  15. Taxing carbon in fuels

    International Nuclear Information System (INIS)

    Arnold, Rob

    2000-01-01

    It is argued that both the Climate Change Levy and the fuel duty tax are outdated even before they are implemented. Apparently, the real problems are not in the bringing of road fuels into the scope of the Climate Change Levy but in introducing reforms to improve integration of greenhouse gases and taxation. Both fuel duty and the Levy are aimed at maximising efficiency and reducing air pollution. The system as it stands does not take into account the development of a market where the management and trading of carbon and greenhouse gases may jeopardise the competitiveness of UK businesses. It is argued that an overhaul of climate and emissions-related law is necessary. The paper is presented under the sub-headings of (i) a fixation on energy; (ii) no focus on CO 2 ; (iii) carbon markets - beyond the levy and (iv) tax structure. (UK)

  16. Steam reforming of fuel to hydrogen in fuel cells

    Science.gov (United States)

    Fraioli, Anthony V.; Young, John E.

    1984-01-01

    A fuel cell capable of utilizing a hydrocarbon such as methane as fuel and having an internal dual catalyst system within the anode zone, the dual catalyst system including an anode catalyst supporting and in heat conducting relationship with a reforming catalyst with heat for the reforming reaction being supplied by the reaction at the anode catalyst.

  17. Molten carbonate fuel cell system

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Yasuhiko; Kinoshita, Mamoru; Murakami, Shuzo; Furukawa, Nobuhiro

    1987-09-26

    Reformed gas or coal gasification gas, etc. is used as the fuel gas for fused carbonate fuel cells, however sulfuric compounds are contained in these gases and even after these gases have been treated beforehand through a desulfurizer, a trace quantity of H/sub 2/S is sent to a fuel electrode. Sulfur oxide which is formed at the time of burning and oxidating the exhaust gas from the fuel electrode is supplied together with the air to an oxygen electrode and becomes sulfate after substituting carbonate, which is the electrolyte of the electrode, causing deterioration of the cell characteristics and durability. With regard to a system that hydrogen rich gas which was reformed from the raw fuel is supplied to a fuel electrode, and its exhaust gas is oxidated through a burner to form carbon dioxide which is supplied together with the air to an oxygen electrode, this invention proposes the prevention of the aforementioned defects by providing at the down stream of the above burner a remover to trap with fused carbonate such sulfur compounds as SO/sub 2/ and SO/sub 3/ in the gas after being oxidated as above. (3 figs)

  18. Hexaaluminate Combustion Catalysts for Fuel Cell Fuel Reformers

    National Research Council Canada - National Science Library

    Thomas, Fred S; Campbell, Timothy J; Shaaban, Aly H; Binder, Michael J; Holcomb, Frank H; Knight, James

    2004-01-01

    .... When heat is produced by combustion of logistics fuel in an open-flame or radiant burner, the rate of hydrogen production in the steam reforming reactor is generally limited by the rate of heat transfer from the burner...

  19. Catalytic autothermal reforming of hydrocarbon fuels for fuel cells

    International Nuclear Information System (INIS)

    Krumpelt, M.; Krause, T.; Kopasz, J.; Carter, D.; Ahmed, S.

    2002-01-01

    Fuel cell development has seen remarkable progress in the past decade because of an increasing need to improve energy efficiency as well as to address concerns about the environmental consequences of using fossil fuel for producing electricity and for propulsion of vehicles[1]. The lack of an infrastructure for producing and distributing H(sub 2) has led to a research effort to develop on-board fuel processing technology for reforming hydrocarbon fuels to generate H(sub 2)[2]. The primary focus is on reforming gasoline, because a production and distribution infrastructure for gasoline already exists to supply internal combustion engines[3]. Existing reforming technology for the production of H(sub 2) from hydrocarbon feedstocks used in large-scale manufacturing processes, such as ammonia synthesis, is cost prohibitive when scaled down to the size of the fuel processor required for transportation applications (50-80 kWe) nor is it designed to meet the varying power demands and frequent shutoffs and restarts that will be experienced during normal drive cycles. To meet the performance targets required of a fuel processor for transportation applications will require new reforming reactor technology developed to meet the volume, weight, cost, and operational characteristics for transportation applications and the development of new reforming catalysts that exhibit a higher activity and better thermal and mechanical stability than reforming catalysts currently used in the production of H(sub 2) for large-scale manufacturing processes

  20. Pyrochlore-type catalysts for the reforming of hydrocarbon fuels

    Science.gov (United States)

    Berry, David A [Morgantown, WV; Shekhawat, Dushyant [Morgantown, WV; Haynes, Daniel [Morgantown, WV; Smith, Mark [Morgantown, WV; Spivey, James J [Baton Rouge, LA

    2012-03-13

    A method of catalytically reforming a reactant gas mixture using a pyrochlore catalyst material comprised of one or more pyrochlores having the composition A.sub.2-w-xA'.sub.wA''.sub.xB.sub.2-y-zB'.sub.yB''.sub.zO.sub.7-.DELTA.. Distribution of catalytically active metals throughout the structure at the B site creates an active and well dispersed metal locked into place in the crystal structure. This greatly reduces the metal sintering that typically occurs on supported catalysts used in reforming reactions, and reduces deactivation by sulfur and carbon. Further, oxygen mobility may also be enhanced by elemental exchange of promoters at sites in the pyrochlore. The pyrochlore catalyst material may be utilized in catalytic reforming reactions for the conversion of hydrocarbon fuels into synthesis gas (H.sub.2+CO) for fuel cells, among other uses.

  1. Fuel cell generator with fuel electrodes that control on-cell fuel reformation

    Science.gov (United States)

    Ruka, Roswell J [Pittsburgh, PA; Basel, Richard A [Pittsburgh, PA; Zhang, Gong [Murrysville, PA

    2011-10-25

    A fuel cell for a fuel cell generator including a housing including a gas flow path for receiving a fuel from a fuel source and directing the fuel across the fuel cell. The fuel cell includes an elongate member including opposing first and second ends and defining an interior cathode portion and an exterior anode portion. The interior cathode portion includes an electrode in contact with an oxidant flow path. The exterior anode portion includes an electrode in contact with the fuel in the gas flow path. The anode portion includes a catalyst material for effecting fuel reformation along the fuel cell between the opposing ends. A fuel reformation control layer is applied over the catalyst material for reducing a rate of fuel reformation on the fuel cell. The control layer effects a variable reformation rate along the length of the fuel cell.

  2. JP-8 Reformation for Fuel Cell Applications

    National Research Council Canada - National Science Library

    Lee, Ivan C; Schmidt, Lanny D

    2004-01-01

    ... (hydrogen and carbon monoxide) selectivity with a rhodium-based catalyst. Time-on-stream experiment indicates that the catalysts remains stable and active for at least 4 hours using a jet fuel (310 ppm sulfur...

  3. Advances in catalysts for internal reforming in high temperature fuel cells

    Science.gov (United States)

    Dicks, A. L.

    Catalytic steam reforming of natural gas is an attractive method of producing the hydrogen required by the present generation of fuel cells. The molten carbonate (MCFC) and solid oxide (SOFC) fuel cells operate at high enough temperatures for the endothermic steam reforming reaction to be carried out within the stack. For the MCFC, the conventional anodes have insufficient activity to catalyse the steam reforming of natural gas. For these cells, internal reforming can be achieved only with the addition of a separate catalyst, preferably located in close proximity to the anode. However, in the so-called `Direct Internal Reforming' configuration, attack from alkali in the MCFC may severely limit catalyst lifetime. In the case of the state-of-the-art SOFC, natural gas can be reformed directly on the nickel cermet anode. However, in the SOFC, temperature variations in the cell caused by the reforming reaction may limit the amount of internal reforming that can be allowed in practice. In addition, some external pre-reforming may be desirable to remove high molecular weight hydrocarbons from the fuel gas, which would otherwise crack to produce elemental carbon. Degradation of the SOFC anode may also be a problem when internal reforming is carried out. This has prompted several research groups to investigate the use of alternative anode materials.

  4. Internal reforming of methane in solid oxide fuel cell systems

    Science.gov (United States)

    Peters, R.; Dahl, R.; Klüttgen, U.; Palm, C.; Stolten, D.

    Internal reforming is an attractive option offering a significant cost reduction, higher efficiencies and faster load response of a solid oxide fuel cell (SOFC) power plant. However, complete internal reforming may lead to several problems which can be avoided with partial pre-reforming of natural gas. In order to achieve high total plant efficiency associated with low energy consumption and low investment costs, a process concept has been developed based on all the components of the SOFC system. In the case of anode gas recycling an internal steam circuit exists. This has the advantage that there is no need for an external steam generator and the steam concentration in the anode gas is reduced. However, anode gas recycling has to be proven by experiments in a pre-reformer and for internal reforming. The addition of carbon dioxide clearly shows a decrease in catalyst activity, while for temperatures higher than 1000 K hydrogen leads to an increase of the measured methane conversion rates.

  5. Gas-to-liquids synthetic fuels for use in fuel cells : reformability, energy density, and infrastructure compatibility.

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, S.; Kopasz, J. P.; Russell, B. J.; Tomlinson, H. L.

    1999-09-08

    The fuel cell has many potential applications, from power sources for electric hybrid vehicles to small power plants for commercial buildings. The choice of fuel will be critical to the pace of its commercialization. This paper reviews the various liquid fuels being considered as an alternative to direct hydrogen gas for the fuel cell application, presents calculations of the hydrogen and carbon dioxide yields from autothermal reforming of candidate liquid fuels, and reports the product gas composition measured from the autothermal reforming of a synthetic fuel in a micro-reactor. The hydrogen yield for a synthetic paraffin fuel produced by a cobalt-based Fischer-Tropsch process was found to be similar to that of retail gasoline. The advantages of the synthetic fuel are that it contains no contaminants that would poison the fuel cell catalyst, is relatively benign to the environment, and could be transported in the existing fuel distribution system.

  6. 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.

  7. Hydrogen generation from biogenic and fossil fuels by autothermal reforming

    Science.gov (United States)

    Rampe, Thomas; Heinzel, Angelika; Vogel, Bernhard

    Hydrogen generation for fuel cell systems by reforming technologies from various fuels is one of the main fields of investigation of the Fraunhofer ISE. Suitable fuels are, on the one hand, gaseous hydrocarbons like methane, propane but also, on the other hand, liquid hydrocarbons like gasoline and alcohols, e.g., ethanol as biogenic fuel. The goal is to develop compact systems for generation of hydrogen from fuel being suitable for small-scale membrane fuel cells. The most recent work is related to reforming according to the autothermal principle — fuel, air and steam is supplied to the reactor. Possible applications of such small-scale autothermal reformers are mobile systems and also miniature fuel cell as co-generation plant for decentralised electricity and heat generation. For small stand-alone systems without a connection to the natural gas grid liquid gas, a mixture of propane and butane is an appropriate fuel.

  8. Pre-reforming of natural gas in solid oxide fuel-cell systems

    Energy Technology Data Exchange (ETDEWEB)

    Peters, R.; Riensche, E.; Cremer, P. [Institute for Materials and Processes Systems IWV 3: Energy Process Engineering, Forschungszentrum Juelich (Germany)

    2000-03-01

    Several measures concerning fuel processing in a solid oxide fuel cell (SOFC) system offer the possibility of significant cost reduction and higher system efficiencies. For SOFC systems, the ratio between internal and pre-reforming has to be optimized on the basis of experimental performance data. Furthermore, anode gas recycling by an injector in front of the pre-reformer can eliminate the steam generator and the corresponding heat of evaporation. A detailed study is carried out on pre-reforming in a reformer of considerable size (10 kW{sub el}). Simulating anode gas recycling with an injector, the influence of carbon dioxide on reactor performance was studied. Also, the dependence of the methanol conversion on mass flow and temperature will be discussed. In addition, some results concerning the dynamic behaviour of the pre-reformer are given. (orig.)

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

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2012-10-09

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

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

    Science.gov (United States)

    Cooper, John F.; Cherepy, Nerine

    2008-10-21

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

  11. Electricity reforms and firm level responses: changing ownership, fuel choices, and technology decisions

    International Nuclear Information System (INIS)

    Shukla, P.R.; Nag, Tirthankar; Biswas, Debashish

    2005-01-01

    This paper examines how electricity reforms in India managed to influence the responses of generating firms. Indian electricity reforms have federal and state character. This paper utilises an extensive survey of generation units in Gujarat State. The findings suggest that reforms have created heterogeneous ownership of generation units. The fuel-mix and technology choices of new owners differ from pre-reform pattern followed by state-owned utilities. The new owners prefer natural gas, sourced technologies internationally, and chosen unit sizes that follow market dynamics. Consequently, the operational performance of power plants has improved. This paper quantifies energy efficiency and carbon intensity baselines, projects their trends, and delineates the contribution of reforms for the state. In generalisation, this paper argues that energy and cost efficiency of power plants across different states shows secular improvements under the reforms, though it cautions that environmental performance would not show such uniformly improving trends. (Author)

  12. Solar hydrogen production: renewable hydrogen production by dry fuel reforming

    Science.gov (United States)

    Bakos, Jamie; Miyamoto, Henry K.

    2006-09-01

    SHEC LABS - Solar Hydrogen Energy Corporation constructed a pilot-plant to demonstrate a Dry Fuel Reforming (DFR) system that is heated primarily by sunlight focusing-mirrors. The pilot-plant consists of: 1) a solar mirror array and solar concentrator and shutter system; and 2) two thermo-catalytic reactors to convert Methane, Carbon Dioxide, and Water into Hydrogen. Results from the pilot study show that solar Hydrogen generation is feasible and cost-competitive with traditional Hydrogen production. More than 95% of Hydrogen commercially produced today is by the Steam Methane Reformation (SMR) of natural gas, a process that liberates Carbon Dioxide to the atmosphere. The SMR process provides a net energy loss of 30 to 35% when converting from Methane to Hydrogen. Solar Hydrogen production provides a 14% net energy gain when converting Methane into Hydrogen since the energy used to drive the process is from the sun. The environmental benefits of generating Hydrogen using renewable energy include significant greenhouse gas and criteria air contaminant reductions.

  13. Reforming options for hydrogen production from fossil fuels for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Ersoz, Atilla; Olgun, Hayati [TUBITAK Marmara Research Center, Institute of Energy, Gebze, 41470 Kocaeli (Turkey); Ozdogan, Sibel [Marmara University Faculty of Engineering, Goztepe, 81040 Istanbul (Turkey)

    2006-03-09

    PEM fuel cell systems are considered as a sustainable option for the future transport sector in the future. There is great interest in converting current hydrocarbon based transportation fuels into hydrogen rich gases acceptable by PEM fuel cells on-board of vehicles. In this paper, we compare the results of our simulation studies for 100kW PEM fuel cell systems utilizing three different major reforming technologies, namely steam reforming (SREF), partial oxidation (POX) and autothermal reforming (ATR). Natural gas, gasoline and diesel are the selected hydrocarbon fuels. It is desired to investigate the effect of the selected fuel reforming options on the overall fuel cell system efficiency, which depends on the fuel processing, PEM fuel cell and auxiliary system efficiencies. The Aspen-HYSYS 3.1 code has been used for simulation purposes. Process parameters of fuel preparation steps have been determined considering the limitations set by the catalysts and hydrocarbons involved. Results indicate that fuel properties, fuel processing system and its operation parameters, and PEM fuel cell characteristics all affect the overall system efficiencies. Steam reforming appears as the most efficient fuel preparation option for all investigated fuels. Natural gas with steam reforming shows the highest fuel cell system efficiency. Good heat integration within the fuel cell system is absolutely necessary to achieve acceptable overall system efficiencies. (author)

  14. Reforming options for hydrogen production from fossil fuels for PEM fuel cells

    Science.gov (United States)

    Ersoz, Atilla; Olgun, Hayati; Ozdogan, Sibel

    PEM fuel cell systems are considered as a sustainable option for the future transport sector in the future. There is great interest in converting current hydrocarbon based transportation fuels into hydrogen rich gases acceptable by PEM fuel cells on-board of vehicles. In this paper, we compare the results of our simulation studies for 100 kW PEM fuel cell systems utilizing three different major reforming technologies, namely steam reforming (SREF), partial oxidation (POX) and autothermal reforming (ATR). Natural gas, gasoline and diesel are the selected hydrocarbon fuels. It is desired to investigate the effect of the selected fuel reforming options on the overall fuel cell system efficiency, which depends on the fuel processing, PEM fuel cell and auxiliary system efficiencies. The Aspen-HYSYS 3.1 code has been used for simulation purposes. Process parameters of fuel preparation steps have been determined considering the limitations set by the catalysts and hydrocarbons involved. Results indicate that fuel properties, fuel processing system and its operation parameters, and PEM fuel cell characteristics all affect the overall system efficiencies. Steam reforming appears as the most efficient fuel preparation option for all investigated fuels. Natural gas with steam reforming shows the highest fuel cell system efficiency. Good heat integration within the fuel cell system is absolutely necessary to achieve acceptable overall system efficiencies.

  15. Actuation method of molten carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Ito, Yasuhiko; Kimoto, Mamoru; Murakami, Shuzo; Furukawa, Nobuhiro

    1987-10-17

    A molten carbonate fuel cell uses reformed gas of crude fuel as fuel gas, but in this gas, CO/sub 2/ is contained in addition to H/sub 2/ and CO which participate the reaction in its fuel electrode. In order to make the reaction of the cell by these gases smoothly, CO/sub 2/ in the exhaust gas from the fuel electrode must be introduced efficiently to its oxygen electrode, however since unreacted H/sub 2/ and CO are contained in the above exhaust gas, they are oxidated and burned once in a boiler and transformed into H/sub 2/O (steam) and CO/sub 2/, then CO/sub 2/ generated in the fuel electrode is added thereto, and afterwards these gases with the air are introduced into the oxygen electrode. However, since this method hinders the high power generation efficiency, in this invention, the exhaust gas from the fuel electrode which burns the reformed gas is introduced into separation chambers separated with CO/sub 2/ permselective membranes, and the mixture of CO/sub 2/ in the above exhaust gas separated with the aforementioned permeable membranes and the air is supplied to the oxygen electrode. At the same time, H/sub 2/ and CO in the above exhaust gas which were not separated with the above permeable membranes are recirculated to the above fuel electrode. (3 figs)

  16. Carbonate fuel cell matrix

    Science.gov (United States)

    Farooque, Mohammad; Yuh, Chao-Yi

    1996-01-01

    A carbonate fuel cell matrix comprising support particles and crack attenuator particles which are made platelet in shape to increase the resistance of the matrix to through cracking. Also disclosed is a matrix having porous crack attenuator particles and a matrix whose crack attenuator particles have a thermal coefficient of expansion which is significantly different from that of the support particles, and a method of making platelet-shaped crack attenuator particles.

  17. Reformate tolerant electrocatalysts in solid polymer fuel cell membrane electrode assemblies

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, S J; Gunner, A G; Thompsett, D; Hards, G A

    1998-12-31

    The aim of the project was to evaluate a series of platinum group metal catalysts which had previously been identified from a wide range of areas related to carbon monoxide (CO) activation, and to demonstrate superior intrinsic reformate tolerance to current platinum/ruthenium technology as anode catalysts for Proton Exchange Membrane Fuel Cells (PEMFC). (author)

  18. Fossil fuel subsidy reform: lessons from the Indonesian case

    International Nuclear Information System (INIS)

    Savatic, Filip

    2016-10-01

    Global assessments of consumption and the Indonesian case show the relevance of non-household consumers of subsidized energy products. As shown in this study, understanding in more nuance how reforms affect them has the potential to improve the reforms that will be developed by policy-makers worldwide. Further study can reinforce the many benefits of successful reform for the countries and societies slowly turning away from these policies of the past. Estimates regarding the amount of public funds utilized to subsidize the production or consumption of fossil fuels are staggering. For 2011, they range from $83 billion in OECD member states, to nearly $4.1 trillion worldwide if environmental externalities are considered. Numerous studies have demonstrated that subsidies repress economic growth, undermine energy sector investment, increase public debt, benefit wealthy citizens over the poor, instigate a rise in illicit activities, and engender greater global and local pollution. The negative effects of fossil fuel subsidies have led numerous governments to reform their energy policies. There has also been a growing international consensus in favor of reform. While the components of successful reform programs have been identified through past case studies, the nature of reforms adopted by several governments that target non-households have not been systematically examined. Since the late 1990s, the Indonesian government has implemented numerous reforms of its fossil fuel subsidies, including measures targeting household as well as non-household energy consumption. In doing so, it has incurred significant fiscal savings. However, an innovative budgetary analysis reveals that households receive a minority, and a declining share, of fossil fuel subsidy funds. This is the case despite the fact that subsidies were implemented to ensure poor households have access to cheap energy. These findings demonstrate the need to consider non-household sectors in the design of fossil

  19. Reforming petroleum-based fuels for fuel cell vehicles : composition-performance relationships

    International Nuclear Information System (INIS)

    Kopasz, J. P.; Miller, L. E.; Ahmed, S.; Devlin, P. R.; Pacheco, M.

    2001-01-01

    Onboard reforming of petroleum-based fuels, such as gasoline, may help ease the introduction of fuel cell vehicles to the marketplace. Although gasoline can be reformed, it is optimized to meet the demands of ICEs. This optimization includes blending to increase the octane number and addition of oxygenates and detergents to control emissions. The requirements for a fuel for onboard reforming to hydrogen are quite different than those for combustion. Factors such as octane number and flame speed are not important; however, factors such as hydrogen density, catalyst-fuel interactions, and possible catalyst poisoning become paramount. In order to identify what factors are important in a hydrocarbon fuel for reforming to hydrogen and what factors are detrimental, we have begun a program to test various components of gasoline and blends of components under autothermal reforming conditions. The results indicate that fuel composition can have a large effect on reforming behavior. Components which may be beneficial for ICEs for their octane enhancing value were detrimental to reforming. Fuels with high aromatic and naphthenic content were more difficult to reform. Aromatics were also found to have an impact on the kinetics for reforming of paraffins. The effects of sulfur impurities were dependent on the catalyst. Sulfur was detrimental for Ni, Co, and Ru catalysts. Sulfur was beneficial for reforming with Pt catalysts, however, the effect was dependent on the sulfur concentration

  20. MEMS-Based Fuel Reformer with Suspended Membrane Structure

    Science.gov (United States)

    Chang, Kuei-Sung; Tanaka, Shuji; Esashi, Masayoshi

    We report a MEMS-based fuel reformer for supplying hydrogen to micro-fuel cells for portable applications. A combustor and a reforming chamber are fabricated at either side of a suspended membrane structure. This design is used to improve the overall thermal efficiency, which is a critical issue to realize a micro-fuel reformer. The suspended membrane structure design provided good thermal isolation. The micro-heaters consumed 0.97W to maintain the reaction zone of the MEMS-based fuel reformer at 200°C, but further power saving is necessary by improving design and fabrication. The conversion rate of methanol to hydrogen was about 19% at 180°C by using evaporated copper as a reforming catalyst. The catalytic combustion of hydrogen started without any assistance of micro-heaters. By feeding the fuel mixture of an equivalence ratio of 0.35, the temperature of the suspended membrane structure was maintained stable at 100°C with a combustion efficiency of 30%. In future works, we will test a micro-fuel reformer by using a micro-combustor to supply heat.

  1. Carbonate fuel cell anodes

    Science.gov (United States)

    Donado, Rafael A.; Hrdina, Kenneth E.; Remick, Robert J.

    1993-01-01

    A molten alkali metal carbonates fuel cell porous anode of lithium ferrite and a metal or metal alloy of nickel, cobalt, nickel/iron, cobalt/iron, nickel/iron/aluminum, cobalt/iron/aluminum and mixtures thereof wherein the total iron content including ferrite and iron of the composite is about 25 to about 80 percent, based upon the total anode, provided aluminum when present is less than about 5 weight percent of the anode. A process for production of the lithium ferrite containing anode by slipcasting.

  2. Energy upcycle in anaerobic treatment: Ammonium, methane, and carbon dioxide reformation through a hybrid electrodeionization–solid oxide fuel cell system

    International Nuclear Information System (INIS)

    Xu, Linji; Dong, Feifei; Zhuang, Huichuan; He, Wei; Ni, Meng; Feng, Shien-Ping; Lee, Po-Heng

    2017-01-01

    Highlights: • EDI-SOFC integrated with AD is introduced for energy extraction from C and N pollutants. • NH_4"+ dissociation to NH_3 and H_2 in EDI avoids C deposition in SOFC. • EDI exhibits nutrient and heavy metal recovery. • SOFCs display its adaptability with NH_3, H_2, and biogas. • Energy balance ratio boosts from 1.11 to 1.75 by EDI-SOFC in a HK landfill plant. - Abstract: To create possibilities for a more sustainable wastewater management, a novel system consisting of electrodeionization (EDI) and solid oxide fuel cells (SOFCs) is proposed in this study. This system is integrated with anaerobic digestion/landfills to capture energy from carbonaceous and nitrogenous pollutants. Both EDI and SOFCs showed good performances. EDI removed 95% and 76% ammonium-nitrogen (NH_4"+-N) from diluted (0.025 M) to concentrated (0.5 M) synthetic ammonium wastewaters, respectively, accompanied by hydrogen production. SOFCs converted the recovered fuels, biogas mixtures of methane and carbon dioxide, to electricity. Under the optimal conditions of EDI (3.0 V applied voltage and 7.5 mm internal electrode distance (IED), and SOFCs (750 °C operating temperature), the system achieved 60% higher net energy output as compared to conventional systems. The estimated energy benefit of this proposed system showed that the net energy balance ratio is enhanced from 1.11 (existing system) to 1.75 (this study) for a local Hong Kong active landfill facility with 10.0 g L"−"1 chemical oxygen demand (COD) and 0.21 M NH_4"+-N. Additionally, an average of 80% inorganic ions (heavy metals and nutrient elements) can be removed from the raw landfill leachate by EDI cell. The results are successful demonstrations of the upgrades of anaerobic processes for energy extraction from wastewater streams.

  3. Fuel saving, carbon dioxide emission avoidance, and syngas production by tri-reforming of flue gases from coal- and gas-fired power stations, and by the carbothermic reduction of iron oxide

    International Nuclear Information System (INIS)

    Halmann, M.; Steinfeld, A.

    2006-01-01

    Flue gases from coal, gas, or oil-fired power stations, as well as from several heavy industries, such as the production of iron, lime and cement, are major anthropogenic sources of global CO 2 emissions. The newly proposed process for syngas production based on the tri-reforming of such flue gases with natural gas could be an important route for CO 2 emission avoidance. In addition, by combining the carbothermic reduction of iron oxide with the partial oxidation of the carbon source, an overall thermoneutral process can be designed for the co-production of iron and syngas rich in CO. Water-gas shift (WGS) of CO to H 2 enables the production of useful syngas. The reaction process heat, or the conditions for thermoneutrality, are derived by thermochemical equilibrium calculations. The thermodynamic constraints are determined for the production of syngas suitable for methanol, hydrogen, or ammonia synthesis. The environmental and economic consequences are assessed for large-scale commercial production of these chemical commodities. Preliminary evaluations with natural gas, coke, or coal as carbon source indicate that such combined processes should be economically competitive, as well as promising significant fuel saving and CO 2 emission avoidance. The production of ammonia in the above processes seems particularly attractive, as it consumes the nitrogen in the flue gases

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

    Science.gov (United States)

    Simson, Amanda

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

  5. Leveraging Fuel Subsidy Reform for Transition in Yemen

    Directory of Open Access Journals (Sweden)

    Olivier Ecker

    2012-10-01

    Full Text Available Yemen is currently undergoing a major political transition, yet many economic challenges—including fuel subsidy reform—remain highly relevant. To inform the transition process with respect to a potential subsidy reform, we use a dynamic computable general equilibrium and microsimulation model for Yemen; we show that overall growth effects of subsidy reduction are positive in general, but poverty can increase or decrease depending on reform design. A promising strategy for a successful reform combines fuel subsidy reduction with direct income transfers to the poorest one-third of households during reform, and productivity-enhancing investment in infrastructure, plus fiscal consolidation. Public investments should be used for integrating economic spaces and restructuring of agricultural, industrial and service value chains in order to create a framework that encourages private-sector-led and job-creating growth.

  6. Leveraging Fuel Subsidy Reform for Transition in Yemen

    OpenAIRE

    Clemens Breisinger; Wilfried Engelke; Olivier Ecker

    2012-01-01

    Yemen is currently undergoing a major political transition, yet many economic challenges—including fuel subsidy reform—remain highly relevant. To inform the transition process with respect to a potential subsidy reform, we use a dynamic computable general equilibrium and microsimulation model for Yemen; we show that overall growth effects of subsidy reduction are positive in general, but poverty can increase or decrease depending on reform design. A promising strategy for ...

  7. A miniature fuel reformer system for portable power sources

    Science.gov (United States)

    Dolanc, Gregor; Belavič, Darko; Hrovat, Marko; Hočevar, Stanko; Pohar, Andrej; Petrovčič, Janko; Musizza, Bojan

    2014-12-01

    A miniature methanol reformer system has been designed and built to technology readiness level exceeding a laboratory prototype. It is intended to feed fuel cells with electric power up to 100 W and contains a complete setup of the technological elements: catalytic reforming and PROX reactors, a combustor, evaporators, actuation and sensing elements, and a control unit. The system is engineered not only for performance and quality of the reformate, but also for its lightweight and compact design, seamless integration of elements, low internal electric consumption, and safety. In the paper, the design of the system is presented by focussing on its miniaturisation, integration, and process control.

  8. A revisit of fossil-fuel subsidies in China: Challenges and opportunities for energy price reform

    International Nuclear Information System (INIS)

    Lin, Boqiang; Ouyang, Xiaoling

    2014-01-01

    Highlights: • We measure fossil-fuel subsidies and effects of subsidy removal in a systematic fashion during 2006–2010. • Fossil-fuel subsidies scale of China was CNY 881.94 billion in 2010, equivalent to 2.59% of GDP. • Impacts of removing subsidies on macroeconomic variables are examined by the CGE model. • Future policy should focus on designing transparent, targeted and efficient energy subsidies. - Abstract: Fossil-fuel subsidies contribute to the extensive growth of energy demand and the related carbon dioxide emissions in China. However, the process of energy price reform is slow, even though China faces increasing problems of energy scarcity and environmental deterioration. This paper focuses on analyzing fossil fuel subsidies in China by estimating subsidies scale and the implications for future reform. We begin by measuring fossil-fuel subsidies and the effects of subsidy removal in a systematic fashion during 2006–2010 using a price-gap approach. Results indicate that the oil price reform in 2009 significantly reduced China’s fossil-fuel subsidies and modified the subsidy structure. Fossil-fuel subsidies scale in China was 881.94 billion CNY in 2010, which was lower than the amount in 2006, equivalent to 2.59% of the GDP. The macro-economic impacts of removing fossil-fuel subsidies are then evaluated by the computable general equilibrium (CGE) model. Results demonstrate that the economic growth and employment will be negatively affected as well as energy demand, carbon dioxide and sulfur dioxide emissions. Finally, policy implications are suggested: first, risks of government pricing of energy are far from negligible; second, an acceptable macroeconomic impact is a criterion for energy price reform in China; third, the future energy policy should focus on designing transparent, targeted and efficient energy subsidies

  9. Determination of optimal reformer temperature in a reformed methanol fuel cell system using ANFIS models and numerical optimization methods

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl

    2015-01-01

    In this work a method for choosing the optimal reformer temperature for a reformed methanol fuel cell system is presented based on a case study of a H3 350 module produced by Serenergy A/S. The method is based on ANFIS models of the dependence of the reformer output gas composition on the reformer...... temperature and fuel flow, and the dependence of the fuel cell voltage on the fuel cell temperature, current and anode supply gas CO content. These models are combined to give a matrix of system efficiencies at different fuel cell currents and reformer temperatures. This matrix is then used to find...... the reformer temperature which gives the highest efficiency for each fuel cell current. The average of this optimal efficiency curve is 32.11% and the average efficiency achieved using the standard constant temperature is 30.64% an increase of 1.47 percentage points. The gain in efficiency is 4 percentage...

  10. Carbon fuel cells with carbon corrosion suppression

    Science.gov (United States)

    Cooper, John F [Oakland, CA

    2012-04-10

    An electrochemical cell apparatus that can operate as either a fuel cell or a battery includes a cathode compartment, an anode compartment operatively connected to the cathode compartment, and a carbon fuel cell section connected to the anode compartment and the cathode compartment. An effusion plate is operatively positioned adjacent the anode compartment or the cathode compartment. The effusion plate allows passage of carbon dioxide. Carbon dioxide exhaust channels are operatively positioned in the electrochemical cell to direct the carbon dioxide from the electrochemical cell.

  11. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2003-03-01

    The program efforts are focused on technology and system optimization for cost reduction, commercial design development, and prototype system field trials. The program is designed to advance the carbonate fuel cell technology from full-size field test to the commercial design. FuelCell Energy, Inc. (FCE) is in the later stage of the multiyear program for development and verification of carbonate fuel cell based power plants supported by DOE/NETL with additional funding from DOD/DARPA and the FuelCell Energy team. FCE has scaled up the technology to full-size and developed DFC{reg_sign} stack and balance-of-plant (BOP) equipment technology to meet product requirements, and acquired high rate manufacturing capabilities to reduce cost. FCE has designed submegawatt (DFC300A) and megawatt (DFC1500 and DFC3000) class fuel cell products for commercialization of its DFC{reg_sign} technology. A significant progress was made during the reporting period. The reforming unit design was optimized using a three-dimensional stack simulation model. Thermal and flow uniformities of the oxidant-In flow in the stack module were improved using computational fluid dynamics based flow simulation model. The manufacturing capacity was increased. The submegawatt stack module overall cost was reduced by {approx}30% on a per kW basis. An integrated deoxidizer-prereformer design was tested successfully at submegawatt scale using fuels simulating digester gas, coal bed methane gas and peak shave (natural) gas.

  12. Stability, carbon resistance, and reactivity toward autothermal reforming of nickel on ceria-based supports

    International Nuclear Information System (INIS)

    Sutthisripok, W.; Laosiripojana, N.

    2004-01-01

    'Full text:' Solid Oxide Fuel Cell (SOFC) normally requires a reformer unit, where the fuel such as natural gas, methane, methanol, or ethanol can be reformed to hydrogen before introducing to the main part of fuel cell. Nickel on commercial supports such as Al2O3, MgO, ZrO2 has been widely reported to be used as the reforming catalyst commercially. Carbon formation and catalyst deactivation are always the main problems of using this type of catalyst. It is well established that CeO2 and CeO2-ZrO2 have been applied as the catalysts in a wide variety of reactions involving oxidation or partial oxidation of hydrocarbons (e.g. automotive catalysis). In order to quantify the performance of nickel on CeO2 and CeO2-ZrO2 supports for reformer application, the stabilities toward methane steam reforming and the carbon formation resistance were studied. After 18 hours, nickel on CeO2-ZrO2 with the Ce/Zr ratio of 3/1 presented the best performance in term of stability and activity. It also provided excellent resistance toward carbon formation compared to commercial Ni/Al2O3. The autothermal reforming of methane over Ni catalyst on CeO2 and CeO2-ZrO2 supports were also investigated. Ni/Ce-ZrO2 with the Ce/ Zr ratio of 3/1 also showed the best performance. The kinetics of this reaction was also studied. In the temperature range of 750-900C, the reaction order in methane was always closed to 1. The catalyst showed a slight positive effect of hydrogen and a negative effect of steam on the steam reforming rate. The addition of oxygen increased the steam reforming rate. However, the productions of CO and H2 decreased with increasing oxygen partial pressure. (author)

  13. Synergistic production of hydrogen using fossil fuels and nuclear energy application of nuclear-heated membrane reformer

    International Nuclear Information System (INIS)

    Hori, M.; Matsui, K.; Tashimo, M.; Yasuda, I.

    2004-01-01

    Processes and technologies to produce hydrogen synergistically by the steam reforming reaction using fossil fuels and nuclear heat are reviewed. Formulas of chemical reactions, required heats for reactions, saving of fuel consumption or reduction of carbon dioxide emission, possible processes and other prospects are examined for such fossil fuels as natural gas, petroleum and coal. The 'membrane reformer' steam reforming with recirculation of reaction products in a closed loop configuration is considered to be the most advantageous among various synergistic hydrogen production methods. Typical merits of this method are: nuclear heat supply at medium temperature below 600 deg. C, compact plant size and membrane area for hydrogen production, efficient conversion of feed fuel, appreciable reduction of carbon dioxide emission, high purity hydrogen without any additional process, and ease of separating carbon dioxide for future sequestration requirements. With all these benefits, the synergistic production of hydrogen by membrane reformer using fossil fuels and nuclear energy can be an effective solution in this century for the world which has to use. fossil fuels any way to some extent while reducing carbon dioxide emission. For both the fossil fuels industry and the nuclear industry, which are under constraint of resource, environment and economy, this production method will be a viable symbiosis strategy for the coming hydrogen economy era. (author)

  14. Preparation of a Ni-MgO-Al2O3 catalyst with high activity and resistance to potassium poisoning during direct internal reforming of methane in molten carbonate fuel cells

    Science.gov (United States)

    Jang, Won-Jun; Jung, You-Shick; Shim, Jae-Oh; Roh, Hyun-Seog; Yoon, Wang Lai

    2018-02-01

    Steam reforming of methane (SRM) is conducted using a series of Ni-MgO-Al2O3 catalysts for direct internal reforming (DIR) in molten carbonate fuel cells (MCFCs). Ni-MgO-Al2O3 catalysts are prepared by the homogeneous precipitation method with a variety of MgO loading amounts ranging from 3 to 15 wt%. In addition, each precursor concentrations are systemically changed (Ni: 1.2-4.8 mol L-1; Mg: 0.3-1.2 mol L-1; Al: 0.4-1.6 mol L-1) at the optimized composition (10 wt% MgO). The effects of MgO loading and precursor concentration on the catalytic performance and resistance against poisoning of the catalyst by potassium (K) are investigated. The Ni-MgO-Al2O3 catalyst with 10 wt% MgO and the original precursor concentration (Ni: 1.2 mol L-1; Mg: 0.3 mol L-1; Al: 0.4 mol L-1) exhibits the highest CH4 conversion and resistance against K poisoning even at the extremely high gas space velocity (GHSV) of 1,512,000 h-1. Excellent SRM performance of the Ni-MgO-Al2O3 catalyst is attributed to strong metal (Ni) to alumina support interaction (SMSI) when magnesium oxide (MgO) is co-precipitated with the Ni-Al2O3. The enhanced interaction of the Ni with MgO-Al2O3 support is found to protect the active Ni species against K poisoning.

  15. Hydrogen from methanol for fuel cells in mobile systems: development of a compact reformer

    Energy Technology Data Exchange (ETDEWEB)

    Hoehlein, B [Forschungszentrum Juelich GmbH (Germany); Boe, M [H. Topsoee A/S, Lyngby (Denmark); Boegild-Hansen, J [H. Topsoee A/S, Lyngby (Denmark); Broeckerhoff, P [Forschungszentrum Juelich GmbH (Germany); Colsman, G [Forschungszentrum Juelich GmbH (Germany); Emonts, B [Forschungszentrum Juelich GmbH (Germany); Menzer, R [Forschungszentrum Juelich GmbH (Germany); Riedel, E

    1996-07-01

    On-board generation of hydrogen from methanol with a reformer in connection with the use of a proton-exchange membrane fuel cell (PEMFC) is an attractive option for a passenger car drive. Special considerations are required to obtain low weight and volume. Furthermore, the PEMFC of today cannot tolerate more than 10 ppm of carbon monoxide in the fuel. Therefore a gas conditioning step is needed after the methanol reformer. Our main research activities focus on the conceptual design of a drive system for a passenger car with methanol reformer and PEMFC: Engineering studies with regard to different aspects of this design including reformer, catalytic burner, gas conditioning, balances of the fuel cycles and basic design of a compact methanol reformer. The work described here was carried out within the framework of a JOULE II project of the European Union (1993-1995). Extensive experimental studies have been carried out at the Forschungszentrum Juelich GmbH (KFA) in Germany and at Haldor Topsoee A/S in Denmark. (orig.)

  16. The agnion Heatpipe-Reformer - operating experiences and evaluation of fuel conversion and syngas composition

    Energy Technology Data Exchange (ETDEWEB)

    Gallmetzer, Georg; Ackermann, Pascal [Highterm Research GmbH, Hettenshausen (Germany); Schweiger, Andreas; Kienberger, Thomas [Highterm Research GmbH, Graz (Austria); Groebl, Thomas; Walter, Heimo [Technische Universitaet Wien, Institut fuer Energietechnik und Thermodynamik, Wien (Austria); Zankl, Markus; Kroener, Martin [Agnion Technologies GmbH, Hettenshausen (Germany)

    2012-09-15

    Fluidized bed gasification of solid fuels is considered as one of the core technologies for future sustainable energy supply. Whereas autothermal oxygen-driven gasification is applied in large-scale substitute natural gas (SNG) and Fischer-Tropsch (FT) plants or small-scale combined heat and power (CHP) plants, the allothermal steam-reforming process of the agnion Heatpipe-Reformer is designed for cost- and fuel-efficient syngas generation at small scales for distributed applications. The Heatpipe-Reformer's pressurized syngas generation provides a number of benefits for SNG, biomass to liquid (BTL) and CHP applications. A modified gas engine concept uses the pressurized and hydrogen-rich syngas for increased performance and tar tolerance at decreased capital expenses. Agnion has installed and operated a 500-kW thermal input pilot plant in Pfaffenhofen, Germany, over the last 2 years, showing stable operation over a variety of operating points. The syngas composition has been measured at values expected by thermodynamic models. An influence of the steam-to-fuel ratio and reformer temperature was observed. Tar and sulphur contents have been monitored and correlated to operation parameters, showing influences on stoichiometry and carbon conversion. The mass and energy streams of the plant were balanced. One of the main observations in the monitoring programme is the fact that syngas output, efficiency and syngas quality correlate to high values if the carbon conversion is high. Carbon conversion rates and cold gas efficiencies are comparably high in respect to today's processes, promising economic and fuel-efficient operation of the Heatpipe-Reformer applications. (orig.)

  17. Reforming of natural gas—hydrogen generation for small scale stationary fuel cell systems

    Science.gov (United States)

    Heinzel, A.; Vogel, B.; Hübner, P.

    The reforming of natural gas to produce hydrogen for fuel cells is described, including the basic concepts (steam reforming or autothermal reforming) and the mechanisms of the chemical reactions. Experimental work has been done with a compact steam reformer, and a prototype of an experimental reactor for autothermal reforming was tested, both containing a Pt-catalyst on metallic substrate. Experimental results on the steam reforming system and a comparison of the steam reforming process with the autothermal process are given.

  18. Increasing carbon and material productivity through environmental tax reform

    International Nuclear Information System (INIS)

    Ekins, Paul; Pollitt, Hector; Summerton, Philip; Chewpreecha, Unnada

    2012-01-01

    Environmental tax reform (ETR), a shift in taxation towards environmental taxes, has been implemented on a small scale in a number of European countries. This paper first gives a short review of the literature about ETR. An Appendix briefly describes the model used for a modelling exercise to explore, through scenarios with low and high international energy prices, the implications of a large-scale ETR in the European Union, sufficient to reach the EU's emission reduction targets for 2020. The paper then reports the results of the exercise. The ETR results in increased carbon and materials, but reduced labour, productivity, with the emission reductions distributed across all sectors as a reduction in the demand for all fossil fuels. There are also small GDP increases for most, but not all, EU countries for all the scenarios, and for the EU as a whole. Both the environmental and macroeconomic outcomes are better with low than with high energy prices, because the former both increases the scale of the ETR required to reach the targets, and reduces the outflow of foreign exchange to pay for energy imports. ETR emerges from the exercise as an attractive and cost-effective policy for environmental improvement. - Highlights: ► European experience with environmental tax reform (ETR) is reviewed. ► Scenarios which meet EU carbon emission targets are modelled. ► The ETR results in increased carbon and materials, but reduced labour, productivity. ► There are small GDP increases for most, but not all, EU countries. ► ETR emerges as an attractive and cost-effective environmental policy.

  19. Tri-reforming and combined reforming of methane for producing syngas with desired hydrogen/carbon monoxide ratios

    Science.gov (United States)

    Pan, Wei

    This dissertation is an exploratory study of a new process concept for direct production of synthesis gas (CO + H2) with desired H 2/CO ratios (1.5--2.0) for methanol synthesis and F-T synthesis, using CO2 together with steam and unconverted O2 in flue gas from fossil fuel-fired electric power plants to react with methane or natural gas. This new process is called tri-reforming, referring to simultaneous CO2-steam-O2 reforming of methane or natural gas. This study included (1) The investigation of carbon formation in the tri-reforming process. For comparison, carbon formation in the combined reforming and CO2 reforming reaction was studied as well. (2) The effect of reaction conditions and feed compositions on equilibrium composition (e.g. H2/CO ratio) and equilibrium conversions in the tri-reforming process. (3) The role of catalysts in the tri-reforming process, especially the effect of catalysts on CO2 conversion in the presence of H 2O and O2. It was clearly evidenced from this study that CO in the product stream is probably the major source of carbon over Ni/Al2O3 in the equimolar CO2-CH4 reforming at 650°C and 1 atm. Addition of either O2 or H2O into the CO 2 reforming reaction system can suppress carbon formation. It was demonstrated that carbon-free operation can be achieved in the tri-reforming process. A thermodynamic comparison of tri-reforming with feed compositions of (H2O+CO2+0.5O2)/CH4 (mol ratio) = 1 showed that O2 improves equilibrium CH4 conversion, yet greatly decreases equilibrium CO2 conversion. H2O in tri-reforming has a significant effect on the H2/CO ratio in the products, while O2 has a minor effect. A kinetic study and catalytic performance tests indicated that the support in a supported catalyst has a significant role in enhancing CO2 conversion to CO in the presence of H2O and O2 in tri-reforming. The Ni/MgO catalyst showed superior performance with close to equilibrium CH4 and CO2 conversions at 850°C, 1 atm, and 32,000 ml

  20. Direct internal steam reforming of ethanol in a solid oxide fuel cell (SOFC) - A thermodynamic analysis

    International Nuclear Information System (INIS)

    Lima da Silva, Aline; De Fraga Malfatti, Celia; Heck, Nestor Cesar; Melo Halmenschlager, Cibele

    2003-01-01

    Among the various types of fuel cells, the solid oxide fuel cell (SOFC) has attracted considerable interest due to the possibility for operation with an internal reformer and higher system efficiency. In SOFC, high operative temperature allows the direct conversion of ethanol into H 2 and CO to take place in the electrochemical cell. Ethanol is considered to be an attractive fuel because it is a renewable energy source and presents some advantages over other green fuels such as safety in storage and handling. Direct internal reforming of ethanol, however, can produce undesirable products that diminish system efficiency and, in the case of carbon deposition over the anode, promote the growth of carbon filaments attached to the anode crystallites which generate massive forces within the electrode structure leading to its rapid breakdown. In this context, a thermodynamic analysis is fundamental to predict the product distribution as well as the conditions favorable for carbon to precipitate inside the cell. Despite of such importance, there are few works in literature dealing with thermodynamic analysis of the direct internal steam reforming of ethanol in fuel cell systems. Hence, the aim of this work is to find appropriate ranges for operating conditions where carbon deposition in SOFC with direct internal reforming operation is not feasible, in temperature range of 500- 1200K. The calculation here is more complicated than that for a reformer because the disappearance of hydrogen and the generation of H 2 O from electrochemical reaction must be taken into account. In the present study, the effects of hydrogen consumption on anode components and on carbon formation are investigated. Equilibrium determinations are performed by the Gibbs energy minimization method, considering the following species: H 2 , H 2 O, CH 4 , CO, CO 2 and C gr . (graphite). The effect of the type of solid electrolyte (oxygen-conducting and hydrogen-conducting) on carbon formation is also

  1. Molten carbonate fuel cell power generation system. Yoyu tansan prime en gata nenryo denchi hatsuden sochi

    Energy Technology Data Exchange (ETDEWEB)

    Uematsu, K; Hatori, S [Ishikawajima-Harima Heavy Industries Co. Ltd., Tokyo (Japan)

    1991-11-01

    In an indirect internal reforming type molten carbonate fuel cell, the reforming temperature is limited less than the operating temperature of the fuel cell, as the heat source for reforming is depended on the reaction heat at about 650 {degree} C of the fuel cell. To improve the reforming rate at the low temperature range, it is considered to increase S/C (ratio of steam to carbon), but this scheme will cause such problems as to increase the voltage drop of the anode, to drop the heat recovery ratio on the cogenerator, to increase the capacity of the heat exchanger, etc. In this invention, in the power generating plant of a molten carbonate fuel cell the inert gas is added to the reforming raw gas, and in addition to the above the gas is mixed with steam and led into the reforming chamber of the plant. When the inert gas which is not directly concerned in the reforming reaction is added to, total mol number increases and the reforming reaction is acceralated. Consequently, the reforming rate can be raised, though the reforming temperature is low. 2 figs.

  2. Hydrogen production via autothermal reforming of Diesel fuel

    Energy Technology Data Exchange (ETDEWEB)

    Pasel, J.; Meissner, J.; Pors, Z.; Cremer, P.; Peters, R.; Stolten, D. [Forschungszentrum Juelich GmbH, Institute for Materials and Processes in Energy Systems (IWV 3), D-52425 Juelich (Germany); Palm, C. [BASF Schwarzheide GmbH, Schipkauer Str. 1, Einheit PFO/I, D-01986 Schwarzheide (Germany)

    2004-08-01

    Hydrogen, for the operation of a polymer electrolyte fuel cell, can be produced by means of autothermal reforming of liquid hydrocarbons. Experiments, especially with ATR 4, which produces a molar hydrogen stream equivalent to an electrical power in the fuel cell of 3 kW, showed that the process should be preferably run in the temperature range between 700 and 850 . This ensures complete hydrocarbon conversion and avoids the formation of considerable amounts of methane and organic compounds in the product water. Experiments with commercial diesel showed promising results but insufficient long-term stability. Experiments concerning the ignition of the catalytic reaction inside the reformer proved that within 60 s after the addition of water and hydrocarbons the reformer reached 95% of its maximum molar hydrogen flow. Measurements, with respect to reformer start-up, showed that it takes approximately 7 min. to heat up the monolith to a temperature of 340 using an external heating device. Modelling is performed, aimed at the modification of the mixing chamber of ATR Type 5, which will help to amend the homogeneous blending of diesel fuel with air and water in the mixing chamber. (Abstract Copyright [2004], Wiley Periodicals, Inc.)

  3. Evaluation of an integrated methane autothermal reforming and high-temperature proton exchange membrane fuel cell system

    International Nuclear Information System (INIS)

    Authayanun, Suthida; Saebea, Dang; Patcharavorachot, Yaneeporn; Arpornwichanop, Amornchai

    2015-01-01

    The aim of this study was to investigate the performance and efficiency of an integrated autothermal reforming and HT-PEMFC (high-temperature proton exchange membrane fuel cell) system fueled by methane. Effect of the inclusion of a CO (carbon monoxide) removal process on the integrated HT-PEMFC system was considered. An increase in the S/C (steam-to-carbon) ratio and the reformer temperature can enhance the hydrogen fraction while the CO formation reduces with increasing S/C ratio. The fuel processor efficiency of the methane autothermal reformer with a WGS (water gas shift reactor) reactor, as the CO removal process, is higher than that without a WGS reactor. A higher fuel processor efficiency can be obtained when the feed of the autothermal reformer is preheated to the reformer temperature. Regarding the cell performance, the reformate gas from the methane reformer operated at T in  = T R and with a high S/C ratio is suitable for the HT-PEMFC system without a WGS reactor. When considering the HT-PEMFC system with a WGS reactor, the CO poisoning has less significant impact on the cell performance and the system can be operated over a broader range to minimize the required total active area. A WGS reactor is necessary for the methane autothermal reforming and HT-PEMFC integrated system with regard to the system efficiency. - Highlights: • An integrated autothermal reforming and HT-PEMFC system was studied. • The HT-PEMFC system with and without a CO removal process was considered. • Parametric analysis was performed to obtain a high system efficiency. • The HT-PEMFC system with the WGS reactor can be run over a broader range. • The efficiencies of the HT-PEMFC systems without and with a WGS reactor were reported

  4. Forest fuel and carbon balances

    International Nuclear Information System (INIS)

    Lundborg, A.

    1994-10-01

    Forest fuel, i.e., branches and tops that remain after felling, are not considered to give a net surplus of carbon dioxide to the atmosphere. In order to, if possible, verify this theory a survey was made of the literature concerning different carbon flows related to forest fuel. Branches and needles that are not utilised as fuel nonetheless eventually become decomposed to carbon dioxide. Branches and stem wood are broken down in occasional cases to 60-80% already within 5-6 years but the decomposition rate varies strongly. A small amount of existing data suggest that branches and stems are broken down almost completely within 60-70 years, and earlier in some cases. Lignin is the component in needles and wood that is the most resistant to decomposition. Decomposition is favoured by optimal temperature and moisture, ground contact and ground animals. Material that is mulched during soil preparation is decomposed considerably faster than material that lies on the soil surface. Felling residues that are left on the soil are a large momentary addition to the soil's reserves of organic material but after a number of years the difference in soil organic material is small between places where fuel has been removed and places where felling residues have been left. High nitrogen deposition, fire control and effective forestry are factors that contribute to the increases in the reserves of soil organic material. It appears to be a good approximation to consider the forest fuel as being a neutral fuel as regards carbon dioxide in a longer perspective. In comparison with other biofuels and fossil fuels, forest fuel appears, together with Salix, to be the fuel that results in very little extra discharge of carbon dioxide or other greenhouse gases during its production, transport and processing. 70 refs, 5 figs, tabs

  5. Analytical study on carbon dioxide reforming of natural gas

    International Nuclear Information System (INIS)

    Ohashi, Hirofumi; Sakaki, Akihiro; Inagaki, Yoshiyuki

    2001-01-01

    In recent years, considerable attention has been paid to carbon dioxide reforming of natural gas, namely CO 2 reforming, since it can produce synthesis gas with low hydrogen-to-carbon ratio preferentially used for production of liquid hydrocarbons in the Fischer-Tropsch and methanol syntheses. This reaction has also very important environmental implications because CO 2 , a green house gas, may be converted into valuable feedstock. In JAERI, CO 2 reforming using the out-of-pile test facility, which is a 1/30 scale model of the HTTR hydrogen production system, is also being considered as an application of steam reforming. For the purpose to estimate the reformer performance in the facility, numerical analysis of natural gas reforming processes of CO 2 and combined reactions with steam and CO 2 has been carried out using mathematical model on heat and mass balance accompanied by chemical reactions. The reformer performance was evaluated in the effect of pressure, temperature, process gas composition and reaction rate constants of the catalyst on conversion, product gas composition and heat consumption of He gas. And also, the potential of carbon formation by CH 4 cracking reaction and Boudouard reaction was estimated. (author)

  6. A methodology for thermodynamic simulation of high temperature, internal reforming fuel cell systems

    Science.gov (United States)

    Matelli, José Alexandre; Bazzo, Edson

    This work presents a methodology for simulation of fuel cells to be used in power production in small on-site power/cogeneration plants that use natural gas as fuel. The methodology contemplates thermodynamics and electrochemical aspects related to molten carbonate and solid oxide fuel cells (MCFC and SOFC, respectively). Internal steam reforming of the natural gas hydrocarbons is considered for hydrogen production. From inputs as cell potential, cell power, number of cell in the stack, ancillary systems power consumption, reformed natural gas composition and hydrogen utilization factor, the simulation gives the natural gas consumption, anode and cathode stream gases temperature and composition, and thermodynamic, electrochemical and practical efficiencies. Both energetic and exergetic methods are considered for performance analysis. The results obtained from natural gas reforming thermodynamics simulation show that the hydrogen production is maximum around 700 °C, for a steam/carbon ratio equal to 3. As shown in the literature, the found results indicate that the SOFC is more efficient than MCFC.

  7. Molten carbonate fuel cell

    Science.gov (United States)

    Kaun, T.D.; Smith, J.L.

    1986-07-08

    A molten electrolyte fuel cell is disclosed with an array of stacked cells and cell enclosures isolating each cell except for access to gas manifolds for the supply of fuel or oxidant gas or the removal of waste gas. The cell enclosures collectively provide an enclosure for the array and effectively avoid the problems of electrolyte migration and the previous need for compression of stack components. The fuel cell further includes an inner housing about and in cooperation with the array enclosure to provide a manifold system with isolated chambers for the supply and removal of gases. An external insulated housing about the inner housing provides thermal isolation to the cell components.

  8. 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.

  9. Design and optimization of a combined fuel reforming and solid oxide fuel cell system with anode off-gas recycling

    International Nuclear Information System (INIS)

    Lee, Tae Seok; Chung, J.N.; Chen, Yen-Cho

    2011-01-01

    Highlights: → In this work, an analytical, parametric study is performed to evaluate the feasibility and performance of a combined fuel reforming and SOFC system. → Specifically the effects of adding the anode off-gas recycling and recirculation components and the CO 2 absorbent unit are investigated. → The AOG recycle ratio increases with increasing S/C ratio and the addition of AOG recycle eliminates the need for external water consumption. → The key finding is that for the SOFC operating at 900 deg. C with the steam to carbon ratio at 5 and no AOG recirculation, the system efficiency peaks. - Abstract: An energy conversion and management concept for a combined system of a solid oxide fuel cell coupled with a fuel reforming device is developed and analyzed by a thermodynamic and electrochemical model. The model is verified by an experiment and then used to evaluate the overall system performance and to further suggest an optimal design strategy. The unique feature of the system is the inclusion of the anode off-gas recycle that eliminates the need of external water consumption for practical applications. The system performance is evaluated as a function of the steam to carbon ratio, fuel cell temperature, anode off gas recycle ratio and CO 2 adsorption percentage. For most of the operating conditions investigated, the system efficiency starts at around 70% and then monotonically decreases to the average of 50% at the peak power density before dropping down to zero at the limiting current density point. From an engineering application point of view, the proposed combined fuel reforming and SOFC system with a range of efficiency between 50% and 70% is considered very attractive. It is suggested that the optimal system is the one where the SOFC operates around 900 deg. C with S/C ratio higher than 3, maximum CO 2 capture, and minimum AOG recirculation.

  10. Modeling of Pem Fuel Cell Systems Including Controls and Reforming Effects for Hybrid Automotive Applications

    National Research Council Canada - National Science Library

    Boettner, Daisie

    2001-01-01

    .... This study develops models for a stand-alone Proton Exchange Membrane (PEM) fuel cell stack, a direct-hydrogen fuel cell system including auxiliaries, and a methanol reforming fuel cell system for integration into a vehicle performance simulator...

  11. Fossil fuel reform in developing states: The case of Trinidad and Tobago, a petroleum producing small Island developing State

    International Nuclear Information System (INIS)

    Scobie, Michelle

    2017-01-01

    Trinidad and Tobago is an oil exporting small island developing state (SIDS) with a 0.12% contribution to global emissions and with important socio-economic challenges. It has producer, electricity and transport fuel subsidies. It is at an interesting juncture in subsidy reform: the government faces the embeddedness of distributive justice norms that are contested by fiscal prudence and environmental stewardship norms. The value of the paper is twofold. First it develops a subsidy intractability framework to explain reform global narratives that highlights: the power of agents, the nature of contested economic, justice and environmental norms and the availability of mechanisms for reform. Second, this framework is used to explain reform narratives and trajectories in Trinidad and Tobago using data from public documents and from a unique elite survey of former and present heads of state, politicians, policy makers and stakeholders. Even in conditions of falling oil prices and national revenue and pressures to reduce emissions, where redistributive justice arguments are heavily embedded in public discourses, those aspects of the subsidy that have developmental or distributive justice goals are more intractable. The results of the study have implications for carbon emission reduction strategies in developing states with fossil fuel reserves. - Highlights: • A subsidy intractability framework is used to analyse fuel subsidy reform. • A sense of entitlement to resources contributes to subsidy intractability. • Global environmental stewardship norms matter less for fuel subsidy reform in SIDS. • Policy space is most determined by international economic conditions in SIDS.

  12. 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.

  13. Steam and partial oxidation reforming options for hydrogen production from fossil fuels for PEM fuel cells

    Directory of Open Access Journals (Sweden)

    Yousri M.A. Welaya

    2012-06-01

    Full Text Available Proton exchange membrane fuel cell (PEM generates electrical power from air and from hydrogen or hydrogen rich gas mixtures. Therefore, there is an increasing interest in converting current hydrocarbon based marine fuels such as natural gas, gasoline, and diesel into hydrogen rich gases acceptable to the PEM fuel cells on board ships. Using chemical flow sheeting software, the total system efficiency has been calculated. Natural gas appears to be the best fuel for hydrogen rich gas production due to its favorable composition of lower molecular weight compounds. This paper presents a study for a 250 kW net electrical power PEM fuel cell system utilizing a partial oxidation in one case study and steam reformers in the second. This study has shown that steam-reforming process is the most competitive fuel processing option in terms of fuel processing efficiency. Partial oxidation process has proved to posses the lowest fuel processing efficiency. Among the options studied, the highest fuel processing efficiency is achieved with natural gas steam reforming system.

  14. Purifier-integrated methanol reformer for fuel cell vehicles

    Science.gov (United States)

    Han, Jaesung; Kim, Il-soo; Choi, Keun-Sup

    We developed a compact, 3-kW, purifier-integrated modular reformer which becomes the building block of full-scale 30-kW or 50-kW methanol fuel processors for fuel cell vehicles. Our proprietary technologies regarding hydrogen purification by composite metal membrane and catalytic combustion by washcoated wire-mesh catalyst were combined with the conventional methanol steam-reforming technology, resulting in higher conversion, excellent quality of product hydrogen, and better thermal efficiency than any other systems using preferential oxidation. In this system, steam reforming, hydrogen purification, and catalytic combustion all take place in a single reactor so that the whole system is compact and easy to operate. Hydrogen from the module is ultrahigh pure (99.9999% or better), hence there is no power degradation of PEMFC stack due to contamination by CO. Also, since only pure hydrogen is supplied to the anode of the PEMFC stack, 100% hydrogen utilization is possible in the stack. The module produces 2.3 Nm 3/h of hydrogen, which is equivalent to 3 kW when PEMFC has 43% efficiency. Thermal efficiency (HHV of product H 2/HHV of MeOH in) of the module is 89% and the power density of the module is 0.77 kW/l. This work was conducted in cooperation with Hyundai Motor Company in the form of a Korean national project. Currently the module is under test with an actual fuel cell stack in order to verify its performance. Sooner or later a full-scale 30-kW system will be constructed by connecting these modules in series and parallel and will serve as the fuel processor for the Korean first fuel cell hybrid vehicle.

  15. Small-scale reforming of diesel and jet fuels to make hydrogen and syngas for fuel cells: A review

    International Nuclear Information System (INIS)

    Xu, Xinhai; Li, Peiwen; Shen, Yuesong

    2013-01-01

    Highlights: • Issues of reforming of heavy hydrocarbon fuels are reviewed. • The advantages of autothermal reforming over other types of reforming are discussed. • The causes and solutions of the major problems for reforming reactors are studied. • Designs and startup strategies for autothermal reforming reactors are proposed. - Abstract: This paper reviews the technological features and challenges of autothermal reforming (ATR) of heavy hydrocarbon fuels for producing hydrogen and syngas onboard to supply fuels to fuel cells for auxiliary power units. A brief introduction at the beginning enumerates the advantages of using heavy hydrocarbon fuels onboard to provide hydrogen or syngas for fuel cells such as solid oxide fuel cells (SOFCs). A detailed review of the reforming and processing technologies of diesel and jet fuels is then presented. The advantages of ATR over steam reforming (SR) and partial oxidation reforming (POX) are summarized, and the ATR reaction is analyzed from a thermodynamic point of view. The causes and possible solutions to the major problems existing in ATR reactors, including hot spots, formation of coke, and inhomogeneous mixing of fuel, steam, and air, are reviewed and studied. Designs of ATR reactors are discussed, and three different reactors, one with a fixed bed, one with monoliths, and one with microchannels are investigated. Novel ideas for design and startup strategies for ATR reactors are proposed at the end of the review

  16. Hydrogen from biomass gas steam reforming for low temperature fuel cell: energy and exergy analysis

    Directory of Open Access Journals (Sweden)

    A. Sordi

    2009-03-01

    Full Text Available This work presents a method to analyze hydrogen production by biomass gasification, as well as electric power generation in small scale fuel cells. The proposed methodology is the thermodynamic modeling of a reaction system for the conversion of methane and carbon monoxide (steam reforming, as well as the energy balance of gaseous flow purification in PSA (Pressure Swing Adsorption is used with eight types of gasification gases in this study. The electric power is generated by electrochemical hydrogen conversion in fuel cell type PEMFC (Proton Exchange Membrane Fuel Cell. Energy and exergy analyses are applied to evaluate the performance of the system model. The simulation demonstrates that hydrogen production varies with the operation temperature of the reforming reactor and with the composition of the gas mixture. The maximum H2 mole fraction (0.6-0.64 mol.mol-1 and exergetic efficiency of 91- 92.5% for the reforming reactor are achieved when gas mixtures of higher quality such as: GGAS2, GGAS4 and GGAS5 are used. The use of those gas mixtures for electric power generation results in lower irreversibility and higher exergetic efficiency of 30-30.5%.

  17. An afterburner-powered methane/steam reformer for a solid oxide fuel cells application

    Science.gov (United States)

    Mozdzierz, Marcin; Chalusiak, Maciej; Kimijima, Shinji; Szmyd, Janusz S.; Brus, Grzegorz

    2018-04-01

    Solid oxide fuel cell (SOFC) systems can be fueled by natural gas when the reforming reaction is conducted in a stack. Due to its maturity and safety, indirect internal reforming is usually used. A strong endothermic methane/steam reforming process needs a large amount of heat, and it is convenient to provide thermal energy by burning the remainders of fuel from a cell. In this work, the mathematical model of afterburner-powered methane/steam reformer is proposed. To analyze the effect of a fuel composition on SOFC performance, the zero-dimensional model of a fuel cell connected with a reformer is formulated. It is shown that the highest efficiency of a solid oxide fuel cell is achieved when the steam-to-methane ratio at the reforming reactor inlet is high.

  18. Vehicle type choice under the influence of a tax reform and rising fuel prices

    DEFF Research Database (Denmark)

    Mabit, Stefan Lindhard

    2014-01-01

    change in new vehicle purchases toward more diesel vehicles and more fuel-efficient vehicles. The paper analyses to what extent a vehicle tax reform similar to the Danish 2007 reform may explain changes in purchasing behaviour. The paper investigates the effects of a tax reform, fuel price changes......, and technological development on vehicle type choice using a mixed logit model. The model allows a simulation of the effect of car price changes that resemble those induced by the tax reform. This effect is compared to the effects of fuel price changes and technology improvements. The simulations show...... that the effect of the tax reform on fuel efficiency is similar to the effect of rising fuel prices while the effect of technological development is much larger. The conclusion is that while the tax reform appeared in the same year as a large increase in fuel efficiency, it seems likely that it only explains...

  19. Development of a methanol reformer for fuel cell vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Lindstroem, Baard

    2003-03-01

    Vehicles powered by fuel cells are from an environmental aspect superior to the traditional automobile using internal combustion of gasoline. Power systems which are based upon fuel cell technology require hydrogen for operation. The ideal fuel cell vehicle would operate on pure hydrogen stored on-board. However, storing hydrogen on-board the vehicle is currently not feasible for technical reasons. The hydrogen can be generated on-board using a liquid hydrogen carrier such as methanol and gasoline. The objective of the work presented in this thesis was to develop a catalytic hydrogen generator for automotive applications using methanol as the hydrogen carrier. The first part of this work gives an introduction to the field of methanol reforming and the properties of a fuel cell based power system. Paper I reviews the catalytic materials and processes available for producing hydrogen from methanol. The second part of this thesis consists of an experimental investigation of the influence of the catalyst composition, materials and process parameters on the activity and selectivity for the production of hydrogen from methanol. In Papers II-IV the influence of the support, carrier and operational parameters is studied. In Paper V an investigation of the catalytic properties is performed in an attempt to correlate material properties with performance of different catalysts. In the third part of the thesis an investigation is performed to elucidate whether it is possible to utilize oxidation of liquid methanol as a heat source for an automotive reformer. In the study which is presented in Paper VI a large series of catalytic materials are tested and we were able to minimize the noble metal content making the system more cost efficient. In the final part of this thesis the reformer prototype developed in the project is evaluated. The reformer which was constructed for serving a 5 k W{sub e} fuel cell had a high performance with near 100 % methanol conversion and CO

  20. Thermodynamic analysis of ethanol/water system in a fuel cell reformer with the Gibbs energy minimization method

    International Nuclear Information System (INIS)

    Lima da Silva, Aline; De Fraga Malfatti, Celia; Heck, Nestor Cesar

    2003-01-01

    The use of fuel cells is a promising technology in the conversion of chemical to electrical energy. Due to environmental concerns related to the reduction of atmospheric pollution and greenhouse gases emissions such as CO 2 , NO x and hydrocarbons, there have been many researches about fuel cells using hydrogen as fuel. Hydrogen gas can be produced by several routes; a promising one is the steam reforming of ethanol. This route may become an important industrial process, especially for sugarcane producing countries. Ethanol is renewable energy and presents several advantages over other sources related to natural availability, storage and handling safety. In order to contribute to the understanding of the steam reforming of ethanol inside the reformer, this work displays a detailed thermodynamic analysis of the ethanol/water system, in the temperature range of 500-1200K, considering different H 2 O/ethanol reforming ratios. The equilibrium determinations were done with the help of the Gibbs energy minimization method using the Generalized Reduced Gradient algorithm (GRG). Based on literature data, the species considered in calculations were: H 2 , H 2 O, CO, CO 2 , CH 4 , C 2 H 4 , CH 3 CHO, C 2 H 5 OH (gas phase) and C gr . (graphite phase). The thermodynamic conditions for carbon deposition (probably soot) on catalyst during gas reforming were analyzed, in order to establish temperature ranges and H 2 O/ethanol ratios where carbon precipitation is not thermodynamically feasible. Experimental results from literature show that carbon deposition causes catalyst deactivation during reforming. This deactivation is due to encapsulating carbon that covers active phases on a catalyst substrate, e.g. Ni over Al 2 O 3 . In the present study, a mathematical relationship between Lagrange multipliers and the carbon activity (with reference to the graphite phase) was deduced, unveiling the carbon activity in the reformer atmosphere. From this, it is possible to foreseen if soot

  1. Modeling and dynamics of an autothermal JP5 fuel reformer for marine fuel cell applications

    International Nuclear Information System (INIS)

    Tsourapas, Vasilis; Sun, Jing; Nickens, Anthony

    2008-01-01

    In this work, a dynamic model of an integrated autothermal reformer (ATR) and proton exchange membrane fuel cell (PEM FC) system and model-based evaluation of its dynamic characteristics are presented. The ATR reforms JP5 fuel into a hydrogen rich flow. The hydrogen is extracted from the reformate flow by a separator membrane (SEP), then supplied to the PEM FC for power generation. A catalytic burner (CB) and a turbine are also incorporated to recuperate energy from the remaining SEP flow that would otherwise be wasted. A dynamic model of this system, based on the ideal gas law and energy balance principles, is developed and used to explore the effects of the operating setpoint selection of the SEP on the overall system efficiency. The analysis reveals that a trade-off exists between the SEP efficiency and the overall system efficiency. Finally the open loop system simulation results are presented and conclusions are drawn on the SEP operation

  2. Investigation of methane steam reforming in planar porous support of solid oxide fuel cell

    International Nuclear Information System (INIS)

    Yang Yongping; Du Xiaoze; Yang Lijun; Huang Yuan; Xian Haizhen

    2009-01-01

    Adopting the porous support in integrated-planar solid oxide fuel cell (IP-SOFC) can reduce the operating temperature by reducing thickness of electrolyte layer, and also, provide internal reforming environment for hydrogen-rich fuel gas. The distributions of reactant and product components, and temperature of methane steam reforming for IP-SOFC were investigated by the developed physical and mathematical model with thermodynamic analysis, in which eleven possible reaction mechanisms were considered by the source terms and Arrhenius relationship. Numerical simulation of the model revealed that the progress of reforming reaction and the distribution of the product, H 2 , were influenced by the operating conditions, included that of temperature, ratio of H 2 O and CH 4 , as well as by the porosity of the supporting material. The simulating results indicate that the methane conversion rate can reach its maximum value under the operating temperature of 800 deg. C and porosity of ε = 0.4, which rather approximate to the practical operating conditions of IP-SOFC. In addition, characteristics of carbon deposition on surface of catalyst were discussed under various operating conditions and configuration parameters of the porous support. The present works provided some theoretical explanations to the numerous experimental observations and engineered practices

  3. A micro fuel reformer integrated with a combustor and a microchannel evaporator

    Science.gov (United States)

    Yoshida, Kazushi; Tanaka, Shuji; Hiraki, Hisashi; Esashi, Masayoshi

    2006-09-01

    This paper describes the development of a micro fuel reformer integrated with a combustor and an evaporator. Fuel reforming tests were performed by using a mixture of methanol and water as reforming fuel and hydrogen as combustion fuel. It was found that the design of the microchannel evaporator is critical to obtain larger hydrogen output. Hydrogen output and CO concentration were investigated by varying the input combustion power at different fuel feeding rates. 32.9 sccm of hydrogen, which is equivalent to 5.9 W in lower heating value, was produced, when input combustion power was 11 W.

  4. Non-catalytic plasma-arc reforming of natural gas with carbon dioxide as the oxidizing agent for the production of synthesis gas or hydrogen

    OpenAIRE

    Blom, P.W.E.; Basson, G.W.

    2013-01-01

    The world’s energy consumption is increasing constantly due to the growing population of the world. The increasing energy consumption has a negative effect on the fossil fuel reserves of the world. Hydrogen has the potential to provide energy for all our needs by making use of fossil fuel such as natural gas and nuclear-based electricity. Hydrogen can be produced by reforming methane with carbon dioxide as the oxidizing agent. Hydrogen can be produced in a Plasma-arc reforming ...

  5. Hydrogen production by steam reforming methanol for polymer electrolyte fuel cells

    International Nuclear Information System (INIS)

    Amphlett, J.C.; Creber, K.A.M.; Davis, J.M.; Mann, R.F.; Peppley, B.A.; Stokes, D.M.

    1993-01-01

    Catalytic steam reforming of methanol has been studied as a means of generating hydrogen for a polymer electrolyte membrane fuel cell. A semi-empirical model of the kinetics of the catalytic steam reforming of methanol over Cu O/Zn O/Al 2 O 3 catalyst has been developed. This model is able to predict the performance of the reformer with respect to the various parameters important in developing an integrated reformer-polymer fuel cell system. A set of sample calculations of reformer temperature and CO production are given. The impact of the performance of the reformer catalyst on the design of the overall fuel cell power system is discussed. The selectivity of the catalyst to minimize CO content in the fuel gas is shown to be more critical than was previously believed. 4 figs., 4 tabs., 11 refs

  6. Carbon-based Fuel Cell

    Energy Technology Data Exchange (ETDEWEB)

    Steven S. C. Chuang

    2005-08-31

    The direct use of coal in the solid oxide fuel cell to generate electricity is an innovative concept for power generation. The C-fuel cell (carbon-based fuel cell) could offer significant advantages: (1) minimization of NOx emissions due to its operating temperature range of 700-1000 C, (2) high overall efficiency because of the direct conversion of coal to CO{sub 2}, and (3) the production of a nearly pure CO{sub 2} exhaust stream for the direct CO{sub 2} sequestration. The objective of this project is to determine the technical feasibility of using a highly active anode catalyst in a solid oxide fuel for the direct electrochemical oxidation of coal to produce electricity. Results of this study showed that the electric power generation from Ohio No 5 coal (Lower Kittanning) Seam, Mahoning County, is higher than those of coal gas and pure methane on a solid oxide fuel cell assembly with a promoted metal anode catalyst at 950 C. Further study is needed to test the long term activity, selectivity, and stability of anode catalysts.

  7. Clean energy from a carbon fuel cell

    Science.gov (United States)

    Kacprzak, Andrzej; Kobyłecki, Rafał; Bis, Zbigniew

    2011-12-01

    The direct carbon fuel cell technology provides excellent conditions for conversion of chemical energy of carbon-containing solid fuels directly into electricity. The technology is very promising since it is relatively simple compared to other fuel cell technologies and accepts all carbon-reach substances as possible fuels. Furthermore, it makes possible to use atmospheric oxygen as the oxidizer. In this paper the results of authors' recent investigations focused on analysis of the performance of a direct carbon fuel cell supplied with graphite, granulated carbonized biomass (biocarbon), and granulated hard coal are presented. The comparison of the voltage-current characteristics indicated that the results obtained for the case when the cell was operated with carbonized biomass and hard coal were much more promising than those obtained for graphite. The effects of fuel type and the surface area of the cathode on operation performance of the fuel cell were also discussed.

  8. Catalytic conversion of methane: Carbon dioxide reforming and oxidative coupling

    KAUST Repository

    Takanabe, Kazuhiro

    2012-01-01

    Natural gas conversion remains one of the essential technologies for current energy needs. This review focuses on the mechanistic aspects of the development of efficient and durable catalysts for two reactions, carbon dioxide reforming and the oxidative coupling of methane. These two reactions have tremendous technological significance for practical application in industry. An understanding of the fundamental aspects and reaction mechanisms of the catalytic reactions reviewed in this study would support the design of industrial catalysts. CO 2 reforming of methane utilizes CO 2, which is often stored in large quantities, to convert as a reactant. Strategies to eliminate carbon deposition, which is the major problem associated with this reaction, are discussed. The oxidative coupling of methane directly produces ethylene in one reactor through a slightly exothermic reaction, potentially minimizing the capital cost of the natural gas conversion process. The focus of discussion in this review will be on the attainable yield of C 2 products by rigorous kinetic analyses.

  9. Nano-structured noble metal catalysts based on hexametallate architecture for the reforming of hydrocarbon fuels

    Science.gov (United States)

    Gardner, Todd H.

    2015-09-15

    Nano-structured noble metal catalysts based on hexametallate lattices, of a spinel block type, and which are resistant to carbon deposition and metal sulfide formation are provided. The catalysts are designed for the reforming of hydrocarbon fuels to synthesis gas. The hexametallate lattices are doped with noble metals (Au, Pt, Rh, Ru) which are atomically dispersed as isolated sites throughout the lattice and take the place of hexametallate metal ions such as Cr, Ga, In, and/or Nb. Mirror cations in the crystal lattice are selected from alkali metals, alkaline earth metals, and the lanthanide metals, so as to reduce the acidity of the catalyst crystal lattice and enhance the desorption of carbon deposit forming moieties such as aromatics. The catalysts can be used at temperatures as high as 1000.degree. C. and pressures up to 30 atmospheres. A method for producing these catalysts and applications of their use also is provided.

  10. Coke-free dry reforming of model diesel fuel by a pulsed spark plasma at low temperatures using an exhaust gas recirculation (EGR) system

    Energy Technology Data Exchange (ETDEWEB)

    Sekine, Yasushi; Furukawa, Naotsugu; Matsukata, Masahiko; Kikuchi, Eiichi, E-mail: ysekine@waseda.jp [Department of Applied Chemistry, Waseda University, 65-301, Okubo, Shinjuku, Tokyo 169-8555 (Japan)

    2011-07-13

    Dry reforming of diesel fuel, an endothermic reaction, is an attractive process for on-board hydrogen/syngas production to increase energy efficiency. For operating this dry reforming process in a vehicle, we can use the exhaust gas from an exhaust gas recirculation (EGR) system as a source of carbon dioxide. Catalytic dry reforming of heavy hydrocarbon is a very difficult reaction due to the high accumulation of carbon on the catalyst. Therefore, we attempted to use a non-equilibrium pulsed plasma for the dry reforming of model diesel fuel without a catalyst. We investigated dry reforming of model diesel fuel (n-dodecane) with a low-energy pulsed spark plasma, which is a kind of non-equilibrium plasma at a low temperature of 523 K. Through the reaction, we were able to obtain syngas (hydrogen and carbon monoxide) and a small amount of C{sub 2} hydrocarbon without coke formation at a ratio of CO{sub 2}/C{sub fuel} = 1.5 or higher. The reaction can be conducted at very low temperatures such as 523 K. Therefore, it is anticipated as a novel and effective process for on-board syngas production from diesel fuel using an EGR system.

  11. Modelling and Optimization of Reforming Systems for use in PEM Fuel Cell

    DEFF Research Database (Denmark)

    Berry, Melissa; Korsgaard, Anders Risum; Nielsen, Mads Pagh

    2004-01-01

    Three different reforming methods for the conversion of natural gas to hydrogen are studied and compared: Steam Reforming (SR), Auto-thermal Reforming (ATR), and Catalytic Partial Oxidation (CPOX). Thermodynamic and kinetic models are developed for the reforming reactors as well as the subsequent...... reactors needed for CO removal to make the synthesis gas suitable for use in a PEM fuel cell. The systems are optimized to minimize the total volume, and must supply adequate hydrogen to a fuel cell with a 100kW load. The resultant system efficiencies are calculated. The CPOX system is the smallest...

  12. Performance and economic assessments of a solid oxide fuel cell system with a two-step ethanol-steam-reforming process using CaO sorbent

    Science.gov (United States)

    Tippawan, Phanicha; Arpornwichanop, Amornchai

    2016-02-01

    The hydrogen production process is known to be important to a fuel cell system. In this study, a carbon-free hydrogen production process is proposed by using a two-step ethanol-steam-reforming procedure, which consists of ethanol dehydrogenation and steam reforming, as a fuel processor in the solid oxide fuel cell (SOFC) system. An addition of CaO in the reformer for CO2 capture is also considered to enhance the hydrogen production. The performance of the SOFC system is analyzed under thermally self-sufficient conditions in terms of the technical and economic aspects. The simulation results show that the two-step reforming process can be run in the operating window without carbon formation. The addition of CaO in the steam reformer, which runs at a steam-to-ethanol ratio of 5, temperature of 900 K and atmospheric pressure, minimizes the presence of CO2; 93% CO2 is removed from the steam-reforming environment. This factor causes an increase in the SOFC power density of 6.62%. Although the economic analysis shows that the proposed fuel processor provides a higher capital cost, it offers a reducing active area of the SOFC stack and the most favorable process economics in term of net cost saving.

  13. Internal reforming characteristics of cermet supported solid oxide fuel cell using yttria stabilized zirconia fed with partially reformed methane

    Energy Technology Data Exchange (ETDEWEB)

    Momma, Akihiko; Takano, Kiyonami; Tanaka, Yohei; Negishi, Akira; Kato, Ken; Nozaki, Ken; Kato, Tohru [Energy Technology Research Institute, National Institute of Advanced Industrial Science and Technology, 1-1-1 Umezono Tsukuba Ibaraki, 305-8568 (Japan); Ichigi, Takenori; Matsuda, Kazuyuki; Ryu, Takashi [Application Development Project, Corporate R and D, NGK Insulators, Ltd., 2-56 Suda-cho Mizuho-ku Nagoya-shi Aichi, 467-8530 (Japan)

    2009-08-01

    In order to investigate the internal reforming characteristics in a cermet supported solid oxide fuel cell (SOFC) using YSZ as the electrolyte, the concentration profiles of the gaseous species along the gas flow direction in the anode were measured. Partially reformed methane using a pre-reformer kept at a constant temperature is supplied to the center of the cell which is operated with a seal-less structure at the gas outlet. The anode gas is sucked in via silica capillaries to the initially evacuated gas tanks. The process is simultaneously carried out using five sampling ports. The sampled gas is analyzed by a gas chromatograph. Most of the measurements are made at the cell temperature (T{sub cell}) of 750 C and at various temperatures of the pre-reformer (T{sub ref}) with various fuel utilizations (U{sub f}) of the cell. The composition of the fuel at the inlet of the anode was confirmed to be almost the same as that theoretically calculated assuming equilibrium at the temperature of the pre-reformer. The effect of internal reforming in the anode is clearly observed as a steady decrease in the methane concentration along the flow axis. The effect of the water-gas shift reaction is also observed as a decrease in the CO{sub 2} concentration and an increase of CO concentration around the gas inlet region, as the water-gas shift reaction inversely proceeds when T{sub cell} is higher than T{sub ref}. The diffusion of nitrogen from the seal-less outermost edge is observed, and the diffusion is confirmed to be more significant as U{sub f} decreases. The observations are compared with the results obtained by the SOFC supported by lanthanum gallate electrolyte. With respect to the internal reforming performance, the cell investigated here is found to be more effective when compared to the previously reported electrolyte supported cell. (author)

  14. Internal reforming characteristics of cermet supported solid oxide fuel cell using yttria stabilized zirconia fed with partially reformed methane

    Science.gov (United States)

    Momma, Akihiko; Takano, Kiyonami; Tanaka, Yohei; Negishi, Akira; Kato, Ken; Nozaki, Ken; Kato, Tohru; Ichigi, Takenori; Matsuda, Kazuyuki; Ryu, Takashi

    In order to investigate the internal reforming characteristics in a cermet supported solid oxide fuel cell (SOFC) using YSZ as the electrolyte, the concentration profiles of the gaseous species along the gas flow direction in the anode were measured. Partially reformed methane using a pre-reformer kept at a constant temperature is supplied to the center of the cell which is operated with a seal-less structure at the gas outlet. The anode gas is sucked in via silica capillaries to the initially evacuated gas tanks. The process is simultaneously carried out using five sampling ports. The sampled gas is analyzed by a gas chromatograph. Most of the measurements are made at the cell temperature (T cell) of 750 °C and at various temperatures of the pre-reformer (T ref) with various fuel utilizations (U f) of the cell. The composition of the fuel at the inlet of the anode was confirmed to be almost the same as that theoretically calculated assuming equilibrium at the temperature of the pre-reformer. The effect of internal reforming in the anode is clearly observed as a steady decrease in the methane concentration along the flow axis. The effect of the water-gas shift reaction is also observed as a decrease in the CO 2 concentration and an increase of CO concentration around the gas inlet region, as the water-gas shift reaction inversely proceeds when T cell is higher than T ref. The diffusion of nitrogen from the seal-less outermost edge is observed, and the diffusion is confirmed to be more significant as U f decreases. The observations are compared with the results obtained by the SOFC supported by lanthanum gallate electrolyte. With respect to the internal reforming performance, the cell investigated here is found to be more effective when compared to the previously reported electrolyte supported cell.

  15. Carbon Capture via Chemical-Looping Combustion and Reforming

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Marcus; Mattisson, Tobias; Ryden, Magnus; Lyngfelt, Anders

    2006-10-15

    Chemical-looping combustion (CLC) is a combustion technology with inherent separation of the greenhouse gas CO{sub 2}. The technique involves the use of a metal oxide as an oxygen carrier which transfers oxygen from combustion air to the fuel, and hence a direct contact between air and fuel is avoided. Two inter-connected fluidized beds, a fuel reactor and an air reactor, are used in the process. In the fuel reactor, the metal oxide is reduced by the reaction with the fuel and in the air reactor; the reduced metal oxide is oxidized with air. The outlet gas from the fuel reactor consists of CO{sub 2} and H{sub 2}O, and almost pure stream of CO{sub 2} is obtained when water is condensed. Considerable research has been conducted on CLC in the last decade with respect to oxygen carrier development, reactor design, system efficiencies and prototype testing. The technique has been demonstrated successfully with both natural gas and syngas as fuel in continuous prototype reactors based on interconnected fluidized beds within the size range 0.3 - 50 kW, using different types of oxygen carriers based on the metals Ni, Co, Fe, Cu and Mn. From these tests it can be established that almost complete conversion of the fuel can be obtained and 100% CO{sub 2} capture is possible. Further, two different types of chemical-looping reforming (CLR) have been presented in recent years. CLR is a technology to produce hydrogen with inherent CO{sub 2} capture. This paper presents an overview of the research performed on CLC and CLR highlights the current status of the technology.

  16. Recent developments in the modeling of molten carbonate fuel cells

    International Nuclear Information System (INIS)

    Wilemski, G.

    1984-01-01

    Modeling of porous electrodes and overall performance of molten carbonate fuel cells is reviewed. Aspects needing improvement are discussed. Some preliminary results on internal methane reforming cells are presented. Successful modeling of molten carbonate fuel cells has been carried out at two levels. The first concerns the prediction of overall cell performance and performance decay, i.e., the calculation of current-voltage curves and their decay rates for various cell operating conditions. The second involves the determination of individual porous electrode performance, i.e., how the electrode overpotential is affected by pore structure, gas composition, degree of electrolyte fill, etc. Both levels are treated mechanistically, as opposed to empirically, using fundamental mathematical descriptions of the relevant physical and chemical phenomena, in order to provide quantitative predictive capability

  17. Integration of high temperature PEM fuel cells with a methanol reformer

    DEFF Research Database (Denmark)

    Pan, Chao; He, Ronghuan; Li, Qingfeng

    2005-01-01

    On-board generation of hydrogen by methanol reforming is an efficient and practical option to fuel PEMFC especially for vehicle propulsion purpose. The methanol reforming can take place at temperatures around 200°C with a nearly 100% conversion at a hydrogen yield of about 400 L–(h–kg catalyst)-1...

  18. Compact reformer for the solid polymer fuel cell policy and best

    Energy Technology Data Exchange (ETDEWEB)

    Goulding, P.S.; Deegan, M.; Gough, A. [Newcastle University (United Kingdom)

    1998-07-01

    This report summarises the results of a study investigating the feasibility of the Compact Reformer concept, and examining its design and manufacture. The development and testing of a hybrid reformer and thin coat catalyst systems are described, and details of the modeling of the reactor, and the optimisation and costing of the solid polymer fuel cell are given. (UK)

  19. Methods of reforming hydrocarbon fuels using hexaaluminate catalysts

    Science.gov (United States)

    Gardner, Todd H [Morgantown, WV; Berry, David A [Morgantown, WV; Shekhawat, Dushyant [Morgantown, WV

    2012-03-27

    A metal substituted hexaaluminate catalyst for reforming hydrocarbon fuels to synthesis gas of the general formula AB.sub.yAl.sub.12-yO.sub.19-.delta., A being selected from alkali metals, alkaline earth metals and lanthanide metals or mixtures thereof. A dopant or surface modifier selected from a transitions metal, a spinel of an oxygen-ion conductor is incorporated. The dopant may be Ca, Cs, K, La, Sr, Ba, Li, Mg, Ce, Co, Fe, Ir, Rh, Ni, Ru, Cu, Pe, Os, Pd, Cr, Mn, W, Re, Sn, Gd, V, Ti, Ag, Au, and mixtures thereof. The oxygen-ion conductor may be a perovskite selected from M'RhO.sub.3, M'PtO.sub.3, M'PdO.sub.3, M'IrO.sub.3, M'RuO.sub.3 wherein M'=Mg, Sr, Ba, La, Ca; a spinel selected from MRh.sub.2O.sub.4, MPt.sub.2O.sub.4, MPd.sub.2O.sub.4, MIr.sub.2O.sub.4, MRu.sub.2O.sub.4 wherein M=Mg, Sr, Ba, La, Ca and mixtures thereof; a florite is selected from M''O.sub.2.

  20. Dynamic modeling of a three-stage low-temperature ethanol reformer for fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Vanesa M; Serra, Maria [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo; Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2009-07-01

    A low-temperature ethanol reformer based on a cobalt catalyst for the production of hydrogen has been designed aiming the feed of a fuel cell for an autonomous low-scale power production unit. The reformer comprises three stages: ethanol dehydrogenation to acetaldehyde and hydrogen over SnO{sub 2} followed by acetaldehyde steam reforming over Co(Fe)/ZnO catalyst and water gas shift reaction. Kinetic data have been obtained under different experimental conditions and a dynamic model has been developed for a tubular reformer loaded with catalytic monoliths for the production of the hydrogen required to feed a 1 kW PEMFC. (author)

  1. Incidence and impact: The regional variation of poverty effects due to fossil fuel subsidy reform

    International Nuclear Information System (INIS)

    Rentschler, Jun

    2016-01-01

    Since fossil fuel subsidy reforms can induce significant distributional shifts and price shocks, effective compensation and social protection programs are crucial. Based on the statistical simulation model by Araar and Verme (2012), this study estimates the regional variability of direct welfare effects of removing fuel subsidies in Nigeria. Uncompensated subsidy removal is estimated to increase the national poverty rate by 3–4% on average. However, uniform cash compensation that appears effective at the national average, is found to fail to mitigate price shocks in 16 of 37 states – thus putting livelihoods (and public support for reforms) at risk. States that are estimated to incur the largest welfare shocks, coincide with hotspots of civil unrest following Nigeria's 2012 subsidy reform attempt. The study illustrates how regionally disaggregated compensation can be revenue neutral, and maintain or reduce pre-reform poverty rates in all states. Overall, it highlights the importance of understanding differences in vulnerability, and designing tailored social protection schemes which ensure public support for subsidy reforms. - Highlights: •Fossil fuel subsidy reforms can induce significant distributional shifts and price shocks. •There is significant regional variation of a reform's effects on poverty rates. •Compensation is key to protect livelihoods and win public support for reform. •Compensation schemes must be carefully tailored to account for regional variation.

  2. Structural analysis of nickel doped cerium oxide catalysts for fuel reforming in solid oxide fuel cells

    Science.gov (United States)

    Cavendish, Rio

    As world energy demands increase, research into more efficient energy production methods has become imperative. Heterogeneous catalysis and nanoscience are used to promote chemical transformations important for energy production. These concepts are important in solid oxide fuel cells (SOFCs) which have attracted attention because of their potential to provide an efficient and environmentally favorable power generation system. The SOFC is also fuel-flexible with the ability to run directly on many fuels other than hydrogen. Internal fuel reforming directly in the anode of the SOFC would greatly reduce the cost and complexity of the device. Methane is the simplest hydrocarbon and a main component in natural gas, making it useful when testing catalysts on the laboratory scale. Nickel (Ni) and gadolinium (Gd) doped ceria (CeO 2) catalysts for potential use in the SOFC anode were synthesized with a spray drying method and tested for catalytic performance using partial oxidation of methane and steam reforming. The relationships between catalytic performance and structure were then investigated using X-ray diffraction, transmission electron microscopy, and environmental transmission electron microscopy. The possibility of solid solutions, segregated phases, and surface layers of Ni were explored. Results for a 10 at.% Ni in CeO2 catalyst reveal a poor catalytic behavior while a 20 at.% Ni in CeO2 catalyst is shown to have superior activity. The inclusion of both 10 at.% Gd and 10 at.% Ni in CeO2 enhances the catalytic performance. Analysis of the presence of Ni in all 3 samples reveals Ni heterogeneity and little evidence for extensive solid solution doping. Ni is found in small domains throughout CeO2 particles. In the 20 at.% Ni sample a segregated, catalytically active NiO phase is observed. Overall, it is found that significant interaction between Ni and CeO2 occurs that could affect the synthesis and functionality of the SOFC anode.

  3. Numerical studies of a compact gasoline reformer for fuel cell vehicle applications

    International Nuclear Information System (INIS)

    McIntyre, C.S.; Harrison, S.J.; Oosthuizen, P.H.; Peppley, B.A.

    2004-01-01

    There has been recent interest in the development of compact fuel processors to produce hydrogen for fuel cell powered vehicles. Gasoline is a promising candidate for distributed or on-board processing because of its high energy density and well-developed infrastructure. A compact fuel processor is under development which utilizes autothermal reforming (ATR) to extract hydrogen from iso-octane, which is used as a surrogate for gasoline. The processor consists of a double-pass packed-bed catalytic reactor to promote partial oxidation, steam reforming, and water-gas-shift reactions. As part of this system development, a commercial computational fluid dynamics (CFD) package was used to model flow and chemical reactions. Reformer performance is presented in terms of hydrogen content in the product stream, reformer efficiency (LHV efficiency) and iso-octane conversion. Results are compared to on-going experimental studies. (author)

  4. System model development for a methanol reformed 5 kW high temperature PEM fuel cell system

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart; Andreasen, Søren Juhl; Kær, Søren Knudsen

    2015-01-01

    This work investigates the system performance when reforming methanol in an oil heated reformer system for a 5 kW fuel cell system. A dynamic model of the system is created and evaluated. The system is divided into 4 separate components. These components are the fuel cell, reformer, burner...... and evaporator, which are connected by two separate oil circuits, one with a burner and reformer and one with a fuel cell and evaporator. Experiments were made on the reformer and measured oil and bed temperatures are presented in multiple working points. The system is examined at loads from 0 to 5000 W electric...

  5. A Novel Cyclic Catalytic Reformer for Hydrocarbon Fuels, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — This proposed Small Business Innovative Research (SBIR) Phase I addresses development of a compact reformer system based on a cyclic partial oxidation (POx)...

  6. State of the art: Multi-fuel reformers for automotive fuel cell applications. Problem identification and research needs

    Energy Technology Data Exchange (ETDEWEB)

    Westerholm, R. [Stockholm Univ. (Sweden). Dept. of Analytical Chemistry; Pettersson, L.J. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

    1999-12-01

    On an assignment from the Transport and Communications Research Board (KFB) a literature study and a study trip to the USA and Great Britain have been performed. The literature study and the study trip was made during late spring and autumn 1999.The purpose of the project was to collect available information about the chemical composition of the product gas from a multi-fuel reformer for a fuel cell vehicle. It was furthermore to identify problems and research needs. The report recommends directions for future major research efforts. The results of the literature study and the study trip led to the following general conclusions: With the technology available today it does not seem feasible to develop a highly efficient and reliable multi-fuel reformer for automotive applications, i. e. for applications where all types of fuels ranging from natural gas to heavy diesel fuels can be used. The potential for developing a durable and reliable system is considerably higher if dedicated fuel reformers are used.The authors propose that petroleum-derived fuels should be designed for potential use in mobile fuel cell applications. In the present literature survey and the site visit discussions we found that there are relatively low emissions from fuel cell engines compared to internal combustion engines. However, the major research work on reformers/fuel cells have been performed during steady-state operation. Emissions during start-up, shutdown and transient operation are basically unknown and must be investigated in more detail. The conclusions and findings in this report are based on open/available information, such as discussions at site visits, reports, scientific publications and symposium proceedings.

  7. Carbonate fuel cells: Milliwatts to megawatts

    Science.gov (United States)

    Farooque, M.; Maru, H. C.

    The carbonate fuel cell power plant is an emerging high efficiency, ultra-clean power generator utilizing a variety of gaseous, liquid, and solid carbonaceous fuels for commercial and industrial applications. The primary mover of this generator is a carbonate fuel cell. The fuel cell uses alkali metal carbonate mixtures as electrolyte and operates at ∼650 °C. Corrosion of the cell hardware and stability of the ceramic components have been important design considerations in the early stages of development. The material and electrolyte choices are founded on extensive fundamental research carried out around the world in the 60s and early 70s. The cell components were developed in the late 1970s and early 1980s. The present day carbonate fuel cell construction employs commonly available stainless steels. The electrodes are based on nickel and well-established manufacturing processes. Manufacturing process development, scale-up, stack tests, and pilot system tests dominated throughout the 1990s. Commercial product development efforts began in late 1990s leading to prototype field tests beginning in the current decade leading to commercial customer applications. Cost reduction has been an integral part of the product effort. Cost-competitive product designs have evolved as a result. Approximately half a dozen teams around the world are pursuing carbonate fuel cell product development. The power plant development efforts to date have mainly focused on several hundred kW (submegawatt) to megawatt-class plants. Almost 40 submegawatt units have been operating at customer sites in the US, Europe, and Asia. Several of these units are operating on renewable bio-fuels. A 1 MW unit is operating on the digester gas from a municipal wastewater treatment plant in Seattle, Washington (US). Presently, there are a total of approximately 10 MW capacity carbonate fuel cell power plants installed around the world. Carbonate fuel cell products are also being developed to operate on

  8. Modelling and optimization of reforming systems for use in PEM fuel cell systems

    International Nuclear Information System (INIS)

    Berry, M.; Korsgaard, A.R.; Nielsen, M.P.

    2004-01-01

    Three different reforming methods for the conversion of natural gas to hydrogen are studied and compared: Steam Reforming (SR), Auto-thermal Reforming (ATR), and Catalytic Partial Oxidation (CPOX). Thermodynamic and kinetic models are developed for the reforming reactors as well as the subsequent reactors needed for CO removal to make the synthesis gas suitable for use in a PEM fuel cell. The systems are optimized to minimize the total volume, and must supply adequate hydrogen to a fuel cell with a 100kW load. The resultant system efficiencies are calculated. The CPOX system is the smallest and exhibits a comparable efficiency to the SR system. The SR system had the best relation between efficiency and volume increase. Optimal temperature profiles within each reactor were found. It was shown that temperature control can significantly reduce reactor volume and increase conversion capabilities. (author)

  9. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes I. Fuel utilization

    Science.gov (United States)

    Kuhn, J.; Kesler, O.

    2015-03-01

    In the first of a two part publication, the effect of fuel utilization (Uf) on carbon deposition rates in solid oxide fuel cell nickel-based anodes was studied. Representative 5-component CH4 reformate compositions (CH4, H2, CO, H2O, & CO2) were selected graphically by plotting the solutions to a system of mass-balance constraint equations. The centroid of the solution space was chosen to represent a typical anode gas mixture for each nominal Uf value. Selected 5-component and 3-component gas mixtures were then delivered to anode-supported cells for 10 h, followed by determination of the resulting deposited carbon mass. The empirical carbon deposition thresholds were affected by atomic carbon (C), hydrogen (H), and oxygen (O) fractions of the delivered gas mixtures and temperature. It was also found that CH4-rich gas mixtures caused irreversible damage, whereas atomically equivalent CO-rich compositions did not. The coking threshold predicted by thermodynamic equilibrium calculations employing graphite for the solid carbon phase agreed well with empirical thresholds at 700 °C (Uf ≈ 32%); however, at 600 °C, poor agreement was observed with the empirical threshold of ∼36%. Finally, cell operating temperatures correlated well with the difference in enthalpy between the supplied anode gas mixtures and their resulting thermodynamic equilibrium gas mixtures.

  10. Measurements on high temperature fuel cells with carbon monoxide-containing fuel gases; Messungen an Hochtemperatur-Brennstoffzellen mit kohlenmonoxidhaltigen Brenngasen

    Energy Technology Data Exchange (ETDEWEB)

    Apfel, Holger

    2012-10-10

    In the present work the different power density of anode-supported high-temperature solid oxide fuel cells (ASC-SOFCs) were examined for carbon monoxide-containing fuels. In addition to wet hydrogen / carbon monoxide mixtures the cells were run with synthetic gas mixtures resembling the products of an autothermal reformer, and actual reformate generated by a 2 kW autothermal reformer. It was found that the power-voltage characteristics of an ASC depends primarily on the open circuit voltages of different gas mixtures, but is nearly independent of the hydrogen concentration of the fuel, although the reaction rates of other potential fuels within the gas mixture, namely carbon monoxide and methane, are much lower that the hydrogen reaction rate. The probable reason is that the main fuel for the electrochemical oxidation within the cell is hydrogen, while the nickel in the base layer of the anode acts as a reformer which replenishes the hydrogen by water reduction via carbon monoxide and methane oxidation.

  11. Carbon monoxide tolerant anodes for proton exchange membrane (PEM) fuel cells. 1. Catalyst development approach

    Energy Technology Data Exchange (ETDEWEB)

    Holleck, G L; Pasquariello, D M; Clauson, S L

    1998-07-01

    PEM fuel cells are highly attractive for distributed power and cogeneration systems. They are efficient and function virtually without noise or pollution. To be competitive PEM fuel cells must operate on fuel mixtures obtained by reforming of widely available natural gas or liquid hydrocarbons. Reformed fuel gas mixtures invariably contain CO, a strong poison for Pt. Therefore CO tolerant anode catalysts are essential for wide spread PEMFC introduction. It is the objective to develop effective CO tolerant fuel cell catalysts based on multi-component platinum-transition metal alloys. Towards this goal the authors have developed a novel approach for the synthesis and performance evaluation of multifunctional ternary alloy fuel cell catalysts. The alloys are prepared as well-defined thin films on standard TFE-bonded carbon substrates via a dc magnetron sputtering technique. The anodes are laminated to Nafion membranes and the electrochemical performance is measured in a representative fuel cell configuration with H{sub 2} and H{sub 2}/CO gas mixtures. The multi-target sputtering technique permits one to reproducibly synthesize true alloy films of controlled composition. The deposit morphology and electrode structure are determined by the standardized TFE bonded carbon substrate. The thin catalyst layer is concentrated at the electrode ionomer interface where it can be fully utilized in a representative fuel cell configuration. Thus, a true comparative fuel cell catalyst evaluation is possible. The effectiveness of this approach will be demonstrated with Pt, Pt-Ru and Pt-Ru-X catalyzed anodes.

  12. Utilisation of high carbon pulverised fuel ash

    OpenAIRE

    Mahmud, Maythem Naji

    2011-01-01

    Coal combustion by-products generated from coal-fired power plant and cause enormous problems for disposal unless a way can be found to utilize these by-products through resource recovery programs. The implementation of air act regulations to reduce NOx emission have resulted millions of tonnes of pulverised fuel ash (PFA) accumulated with high percentage of unburned carbon made it un-saleable for the cement industry. Moreover, alternative fuels such as biomass and import coals were suggested...

  13. Gas composition modeling in a reformed Methanol Fuel Cell system using adaptive Neuro-Fuzzy Inference Systems

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Shaker, Hamid Reza

    2013-01-01

    This work presents a method for modeling the gas composition in a Reformed Methanol Fuel Cell system. The method is based on Adaptive Neuro-Fuzzy-Inference-Systems which are trained on experimental data. The developed models are of the H2, CO2, CO and CH3OH mass flows of the reformed gas. The ANFIS......, or fuel cell diagnostics systems....

  14. Control and experimental characterization of a methanol reformer for a 350 W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart

    2013-01-01

    is the water and methanol mixture fuel flow and the burner fuel/air ratio and combined flow. An experimental setup is presented capable of testing the methanol reformer used in the Serenergy H3 350 Mobile Battery Charger; a high temperature polymer electrolyte membrane (HTPEM) fuel cell system......This work presents a control strategy for controlling the methanol reformer temperature of a 350 W high temperature polymer electrolyte membrane fuel cell system, by using a cascade control structure for reliable system operation. The primary states affecting the methanol catalyst bed temperature....... The experimental system consists of a fuel evaporator utilizing the high temperature waste gas from the cathode air cooled 45 cell HTPEM fuel cell stack. The fuel cells used are BASF P1000 MEAs which use phosphoric acid doped polybenzimidazole membranes. The resulting reformate gas output of the reformer system...

  15. Low carbon fuel and chemical production from waste gases

    Energy Technology Data Exchange (ETDEWEB)

    Simpson, S.; Liew, F.M.; Daniell, J.; Koepke, M. [LanzaTech, Ltd., Auckland (New Zealand)

    2012-07-01

    LanzaTech has developed a gas fermentation platform for the production of alter native transport fuels and commodity chemicals from carbon monoxide, hydrogen and carbon dioxide containing gases. LanzaTech technology uses these gases in place of sugars as the carbon and energy source for fermentation thereby allowing a broad spectrum of resources to be considered as an input for product synthesis. At the core of the Lanzatech process is a proprietary microbe capable of using gases as the only carbon and energy input for product synthesis. To harness this capability for the manufacture of a diverse range of commercially valuable products, the company has developed a robust synthetic biology platform to enable a variety of novel molecules to be synthesised via gas fermentation. LanzaTech initially focused on the fermentation of industrial waste gases for fuel ethanol production. The company has been operating pilot plant that uses direct feeds of steel making off gas for ethanol production for over 24 months. This platform technology has been further successfully demonstrated using a broad range of gas inputs including gasified biomass and reformed natural gas. LanzaTech has developed the fermentation, engineering and control systems necessary to efficiently convert gases to valuable products. A precommercial demonstration scale unit processing steel mill waste gases was commissioned in China during the 2{sup nd} quarter of 2012. Subsequent scale-up of this facility is projected for the 2013 and will represent the first world scale non-food based low carbon ethanol project. More recently LanzaTech has developed proprietary microbial catalysts capable of converting carbon dioxide in the presence of hydrogen directly to value added chemicals, where-in CO{sub 2} is the sole source of carbon for product synthesis. Integrating the LanzaTech technology into a number of industrial facilities, such as steel mills, oil refineries and other industries that emit Carbon bearing

  16. Dynamic modeling and controllability analysis of an ethanol reformer for fuel cell application

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Vanesa M.; Serra, Maria; Riera, Jordi [Institut de Robotica i Informatica Industrial (CSIC-UPC), Llorens i Artigas 4-6, 08028 Barcelona (Spain); Lopez, Eduardo [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain); Planta Piloto de Ingenieria Quimica (CONICET-UNS), Camino de la Carrindanga km7, 8000 Bahia Blanca (Argentina); Llorca, Jordi [Institut de Tecniques Energetiques, Universitat Politecnica de Catalunya, Diagonal 647, ed. ETSEIB, 08028 Barcelona (Spain)

    2010-09-15

    This work presents a controllability analysis of a low temperature ethanol reformer based on a cobalt catalyst for fuel cell application. The study is based on a non-linear dynamic model of a reformer which operates in three separate stages: ethanol dehydrogenation to acetaldehyde and hydrogen, acetaldehyde steam reforming, and water-gas-shift reaction. The controllability analysis is focused on the rapid dynamics due to mass balances and is based on a linearization of the complex non-linear model of the reformer. RGA, CN and MRI analysis tools are applied to the linear model suggesting that a good performance can be obtained with decentralized control for frequencies up to 0.1 rad s{sup -1}. (author)

  17. Thermodynamic analysis of direct internal reforming of methane and butane in proton and oxygen conducting fuel cells

    NARCIS (Netherlands)

    Biesheuvel, P.M.; Geerlings, J.J.C.

    2008-01-01

    We present results of a thermodynamic analysis of direct internal reforming fuel cells, based on either a proton conducting fuel cell (FC-H+) or an oxygen ion conducting fuel cell (FC-O2-). We analyze the option of methane as fuel as well as butane. The model self-consistently combines all chemical

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

    Science.gov (United States)

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

    2017-04-01

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

  19. 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...

  20. Ethanol internal steam reforming in intermediate temperature solid oxide fuel cell

    Science.gov (United States)

    Diethelm, Stefan; Van herle, Jan

    This study investigates the performance of a standard Ni-YSZ anode supported cell under ethanol steam reforming operating conditions. Therefore, the fuel cell was directly operated with a steam/ethanol mixture (3 to 1 molar). Other gas mixtures were also used for comparison to check the conversion of ethanol and of reformate gases (H 2, CO) in the fuel cell. The electrochemical properties of the fuel cell fed with four different fuel compositions were characterized between 710 and 860 °C by I- V and EIS measurements at OCV and under polarization. In order to elucidate the limiting processes, impedance spectra obtained with different gas compositions were compared using the derivative of the real part of the impedance with respect of the natural logarithm of the frequency. Results show that internal steam reforming of ethanol takes place significantly on Ni-YSZ anode only above 760 °C. Comparisons of results obtained with reformate gas showed that the electrochemical cell performance is dominated by the conversion of hydrogen. The conversion of CO also occurs either directly or indirectly through the water-gas shift reaction but has a significant impact on the electrochemical performance only above 760 °C.

  1. High power density carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Doyon, J.; Allen, J. [Energy Research Corp., Danbury, CT (United States)

    1996-12-31

    Carbonate fuel cell is a highly efficient and environmentally clean source of power generation. Many organizations worldwide are actively pursuing the development of the technology. Field demonstration of multi-MW size power plant has been initiated in 1996, a step toward commercialization before the turn of the century, Energy Research Corporation (ERC) is planning to introduce a 2.85MW commercial fuel cell power plant with an efficiency of 58%, which is quite attractive for distributed power generation. However, to further expand competitive edge over alternative systems and to achieve wider market penetration, ERC is exploring advanced carbonate fuel cells having significantly higher power densities. A more compact power plant would also stimulate interest in new markets such as ships and submarines where space limitations exist. The activities focused on reducing cell polarization and internal resistance as well as on advanced thin cell components.

  2. Development of Sulfur and Carbon Tolerant Reforming Alloy Catalysts Aided Fundamental Atomistic Insights

    Energy Technology Data Exchange (ETDEWEB)

    Suljo Linic

    2008-12-31

    Current hydrocarbon reforming catalysts suffer from rapid carbon and sulfur poisoning. Even though there is a tremendous incentive to develop more efficient catalysts, these materials are currently formulated using inefficient trial and error experimental approaches. We have utilized a hybrid experimental/theoretical approach, combining quantum Density Functional Theory (DFT) calculations and various state-of-the-art experimental tools, to formulate carbon tolerant reforming catalysts. We have employed DFT calculations to develop molecular insights into the elementary chemical transformations that lead to carbon poisoning of Ni catalysts. Based on the obtained molecular insights, we have identified, using DFT quantum calculation, various Ni alloy catalysts as potential carbon tolerant reforming catalysts. The alloy catalysts were synthesized and tested in steam reforming and partial oxidation of methane, propane, and isooctane. We demonstrated that the alloy catalysts are much more carbon-tolerant than monometallic Ni catalysts under nearly stoichiometric steam-to-carbon ratios. Under these conditions, monometallic Ni is rapidly poisoned by sp2 carbon deposits. The research approach is distinguished by two characteristics: (a) knowledge-based, bottomup approach, compared to the traditional trial and error approach, allows for a more efficient and systematic discovery of improved catalysts. (b) the focus is on exploring alloy materials which have been largely unexplored as potential reforming catalysts.

  3. Development of Sulfur and Carbon Tolerant Reforming Alloy Catalysts Aided by Fundamental Atomistics Insights

    Energy Technology Data Exchange (ETDEWEB)

    Suljo Linic

    2006-08-31

    Current hydrocarbon reforming catalysts suffer from rapid carbon and sulfur poisoning. Even though there is a tremendous incentive to develop more efficient catalysts, these materials are currently formulated using inefficient trial and error experimental approaches. We have utilized a novel hybrid experimental/theoretical approach, combining quantum Density Functional Theory (DFT) calculations and various state-of-the-art experimental tools, to formulate carbon tolerant reforming catalysts. We have employed DFT calculations to develop molecular insights into the elementary chemical transformations that lead to carbon poisoning of Ni catalysts. Based on the obtained molecular insights, we have identified, using DFT quantum calculation, Sn/Ni alloy as a potential carbon tolerant reforming catalyst. Sn/Ni alloy was synthesized and tested in steam reforming of methane, propane, and isooctane. We demonstrated that the alloy catalyst is carbon-tolerant under nearly stoichiometric steam-to-carbon ratios. Under these conditions, monometallic Ni is rapidly poisoned by sp2 carbon deposits. The research approach is distinguished by a few characteristics: (a) Knowledge-based, bottom-up approach, compared to the traditional trial and error approach, allows for a more efficient and systematic discovery of improved catalysts. (b) The focus is on exploring alloy materials which have been largely unexplored as potential reforming catalysts.

  4. Compact methanol reformer test for fuel-cell powered light-duty vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Emonts, B; Hoehlein, B; Peters, R [Forschungszentrum Juelich GmbH (Germany). Inst. fuer Energieverfahrenstechnik (IEV); Hansen, J B; Joergensen, S L [Haldor Topsoe A/S, Lyngby (Denmark)

    1998-03-15

    On-board production of hydrogen from methanol based on a steam reformer in connection with the use of low-temperature fuel-cells (PEMFC) is an attractive option as energy conversion unit for light-duty vehicles. A steam reforming process at higher pressures with an external burner offers advantages in comparison to a steam reformer with integrated partial oxidation in terms of total efficiency for electricity production. The main aim of a common project carried out by the Forschungszentrum Juelich (FZJ), Haldor Topsoee A/S (HTAS) and Siemens AG is to design, to construct and to test a steam reformer reactor concept (HTAS) with external catalytic burner (FZJ) as heat source as well as catalysts for heterogeneously catalyzed hydrogen production (HTAS), concepts for gas treatment (HTAS, FZJ) and a low-temperature fuel cell (Siemens). Based on the experimental results obtained so far concerning methanol reformers, catalytic burners and gas conditioning units, our report describes the total system, a test unit and preliminary test results related to a hydrogen production capacity of 50 kW (LHV) and dynamic operating conditions. This hydrogen production system is aimed at reducing the specific weight (<2 kg/kW{sub th} or 4 kg/kW{sub el}) combined with high efficiency for net electricity generation from methanol (about 50%) and low specific emissions. The application of Pd-membranes as gas cleaning unit fulfill the requirements with high hydrogen permeability and low cost of the noble metal. (orig.)

  5. Performance evaluation of a proof-of-concept 70 W internal reforming methanol fuel cell system

    Science.gov (United States)

    Avgouropoulos, G.; Schlicker, S.; Schelhaas, K.-P.; Papavasiliou, J.; Papadimitriou, K. D.; Theodorakopoulou, E.; Gourdoupi, N.; Machocki, A.; Ioannides, T.; Kallitsis, J. K.; Kolb, G.; Neophytides, S.

    2016-03-01

    A proof-of-concept 70 W Internal Reforming Methanol Fuel Cell (IRMFC) stack including Balance-of-Plant (BoP) was designed, assembled and tested. Advent TPS® high-temperature, polymer electrolyte membrane electrode assemblies were employed for fuel cell operation at 200 °C. In order to avoid phosphoric acid poisoning of the reformer, the anode electrocatalyst of each cell was indirectly adjoined, via a separation plate, to a highly active CuMnAlOx catalyst coated onto copper foam, which served as methanol reforming layer. The reformer was in-situ converting the methanol/steam feed to the required hydrogen (internal reforming concept) at 200 °C, which was readily oxidized at the anode electrodes. The operation of the IRMFC was supported through a number of BoP components consisting of a start-up subsystem (air blower, evaporator and monolithic burner), a combined afterburner/evaporator device, methanol/water supply and data acquisition units (reactants/products analysis, temperature control, flow control, system load/output control). Depending on the composition of the liquid MeOH/H2O feed streams, current densities up to 0.18 A cm-2 and power output up to 70 W could be obtained with remarkable repeatability. Specific targets for improvement of the efficiency were identified.

  6. An estimation of the water balance in a reformer/fuel-cells system

    Energy Technology Data Exchange (ETDEWEB)

    Jovan, Vladimir [Jo-ef Stefan Institute and Centre of Excellence Low-Carbon Technologies (Slovenia); Cufar, Alja [University of Ljubljana, Faculty of Mathematics and Physics (Slovenia)], e-mail: vladimir.jovan@ijs.si

    2011-07-01

    PEM fuel cells use hydrogen as fuel. Since it is a very light element, its energy density is small despite its high caloric value. Thus hydrogen storage requires a lot of space. One possible solution is simultaneous production of hydrogen from higher-density materials, such as methanol. The object of this paper is to determine what is the total water balance in a system consisting of a methanol reformer and a fuel-cells-based generator set, and to determine if water should be supplied to, or removed from, the system. Based on relatively little information obtained from technical sources and on some simple assumptions, this paper presents a model which helps to determine the actual water balance in the system. In conclusion, commercially available fuel-cell systems with realistic water production can be used for fuel reforming purposes in the methanol reformer. It is also shown that under normal operating conditions, and using commercially available devices, there is always an excess of water produced.

  7. Microplasma reforming of hydrocarbons for fuel cell power

    Science.gov (United States)

    Besser, R. S.; Lindner, P. J.

    The implementation of a microplasma approach for small scale reforming processes is explored as an alternative to more standard catalyst-based processes. Plasmas are a known approach to activating a chemical reaction in place of catalysts, and microplasmas are particularly attractive owing to their extremely high electron and power densities. Their inherent compactness gives them appeal for portable applications, but their modularity leads to scalability for higher capacity. We describe the realization of experimental microplasma reactors based on the microhollow cathode discharge (MHCD) structure by silicon micromachining for device fabrication. Experiments were carried out with model hydrocarbons methane and butane in the reactors within a microfluidic flow and analytical setup. We observe several key phenomena, including the ability to liberate hydrogen from the hydrocarbons at temperatures near ambient and sub-Watt input power levels, the tendency toward hydrocarbon decomposition rather than oxidation even in the presence of oxygen, and the need for a neutral carrier to obtain conversion. Mass and energy balances on these experiments revealed conversions up to nearly 50%, but the conversion of electrical power input to chemical reaction enthalpy was only on the order of 1%. These initial, exploratory results were recorded with devices and at process settings without optimization, and are hence promising for an emerging, catalyst-free reforming approach.

  8. The potential role of a carbon tax in U.S. fiscal reform

    Energy Technology Data Exchange (ETDEWEB)

    McKibbin, Warwick [Australian National Univ. (Australia); The Brookings Institution, Washington, DC (United States); Morris, Adele [The Brookings Institution, Washington, DC (United States); Wilcoxen, Peter [Syracuse University, NY (United States); The Brookings Institution, Washington, DC (United States); Cai, Yiyong [Commonwealth Scientific and Industrial Research Organization, Australian National Univ. (Australia)

    2012-07-24

    This paper examines fiscal reform options in the United States with an intertemporal computable general equilibrium model of the world economy called G-Cubed. Six policy scenarios explore two overarching issues: (1) the effects of a carbon tax under alternative assumptions about the use of the resulting revenue, and (2) the effects of alternative measures that could be used to reduce the budget deficit. We examine a simple excise tax on the carbon content of fossil fuels in the U.S. energy sector starting immediately at $15 per metric ton of carbon dioxide (CO2) and rising at 4 percent above inflation each year through 2050. We investigate policies that allow the revenue from the illustrative carbon tax to reduce the long run federal budget deficit or the marginal tax rates on labor and capital income. We also compare the carbon tax to other means of reducing the deficit by the same amount. We find that the carbon tax will raise considerable revenue: $80 billion at the outset, rising to $170 billion in 2030 and $310 billion by 2050. It also significantly reduces U.S. CO2 emissions by an amount that is largely independent of the use of the revenue. By 2050, annual CO2 emissions fall by 2.5 billion metric tons (BMT), or 34 percent, relative to baseline, and cumulative emissions fall by 40 BMT through 2050. The use of the revenue affects both broad economic impacts and the composition of GDP across consumption, investment and net exports. In most scenarios, the carbon tax lowers GDP slightly, reduces investment and exports, and increases imports. The effect on consumption varies across policies and can be positive if households receive the revenue as a lump sum transfer. Using the revenue for a capital tax cut, however, is significantly different than the other policies. In that case, investment booms, employment rises, consumption declines slightly, imports increase, and overall GDP rises significantly relative to baseline through about 2040. Thus, a tax reform that

  9. Simulation study of a proton exchange membrane (PEM) fuel cell system with autothermal reforming

    Energy Technology Data Exchange (ETDEWEB)

    Ersoz, Atilla [TUBITAK Marmara Research Centre, Energy Systems and Environmental Research Institute, 41470 Gebze, Kocaeli (Turkey); Olgun, Hayati [TUBITAK Marmara Research Centre, Energy Systems and Environmental Research Institute, 41470 Gebze, Kocaeli (Turkey); Ozdogan, Sibel [Marmara University, Faculty of Engineering, Department of Mechanical Engineering, 81040 Goztepe, Istanbul (Turkey)

    2006-08-15

    This paper presents the results of a study for a 100 kW net electrical power PEM fuel cell system. The major system components are an autothermal reformer, high and low temperature shift reactors, a preferential oxidation reactor, a PEM fuel cell, a combustor and an expander. Intensive heat integration within the PEM fuel cell system has been necessary to achieve acceptable net electrical efficiency levels. The calculations comprise the auxiliary equipment such as pumps, compressors, heaters, coolers, heat exchangers and pipes. The process simulation package 'ASPEN-HYSYS 3.1' has been used along with conventional calculations. The operation conditions of the autothermal reformer have been studied in detail to determine the values, which lead to the production of a hydrogen rich gas mixture with CO concentration at ppm level. The operation parameters of the other reactors have been determined considering the limitations implied by the catalysts involved. A gasoline type hydrocarbon fuel has been studied as the source for hydrogen production. The chemical composition of the hydrocarbon fuel affects the favorable operation conditions of autothermal reforming and the following fuel purification steps. Thermal efficiencies have been calculated for all of the major system components for selected operation conditions. The fuel cell stack efficiency has been calculated as a function of the number of cells (500-1250 cells). Efficiencies of all of the major system components along with auxiliary unit efficiencies determine the net electrical efficiency of the PEM fuel cell system. The obtained net electrical efficiency levels are between 30 (500 cells) and 37% (1250 cells). Hence, they are comparable with or higher than those of the conventional gasoline based internal combustion engine systems, in terms of the mechanical power efficiency.

  10. Simulation study of a proton exchange membrane (PEM) fuel cell system with autothermal reforming

    International Nuclear Information System (INIS)

    Ersoz, Atilla; Olgun, Hayati; Ozdogan, Sibel

    2006-01-01

    This paper presents the results of a study for a 100 kW net electrical power PEM fuel cell system. The major system components are an autothermal reformer, high and low temperature shift reactors, a preferential oxidation reactor, a PEM fuel cell, a combustor and an expander. Intensive heat integration within the PEM fuel cell system has been necessary to achieve acceptable net electrical efficiency levels. The calculations comprise the auxiliary equipment such as pumps, compressors, heaters, coolers, heat exchangers and pipes. The process simulation package 'ASPEN-HYSYS 3.1' has been used along with conventional calculations. The operation conditions of the autothermal reformer have been studied in detail to determine the values, which lead to the production of a hydrogen rich gas mixture with CO concentration at ppm level. The operation parameters of the other reactors have been determined considering the limitations implied by the catalysts involved. A gasoline type hydrocarbon fuel has been studied as the source for hydrogen production. The chemical composition of the hydrocarbon fuel affects the favorable operation conditions of autothermal reforming and the following fuel purification steps. Thermal efficiencies have been calculated for all of the major system components for selected operation conditions. The fuel cell stack efficiency has been calculated as a function of the number of cells (500-1250 cells). Efficiencies of all of the major system components along with auxiliary unit efficiencies determine the net electrical efficiency of the PEM fuel cell system. The obtained net electrical efficiency levels are between 30 (500 cells) and 37% (1250 cells). Hence, they are comparable with or higher than those of the conventional gasoline based internal combustion engine systems, in terms of the mechanical power efficiency

  11. Materials testing for molten carbonate fuel cells

    International Nuclear Information System (INIS)

    Di Mario, F.; Frangini, S.

    1995-01-01

    Unlike conventional generation systems fuel cells use an electrochemical reaction between a fossil fuel and an oxidant to produce electricity through a flame less combustion process. As a result, fuel cells offer interesting technical and operating advantages in terms of conversion efficiencies and environmental benefits due to very low pollutant emissions. Among the different kinds of fuel cells the molten carbonate fuel cells are currently being developed for building compact power generation plants to serve mainly in congested urban areas in virtue of their higher efficiency capabilities at either partial and full loads, good response to power peak loads, fuel flexibility, modularity and, potentially, cost-effectiveness. Starting from an analysis of the most important degradative aspects of the corrosion of the separator plate, the main purpose of this communication is to present the state of the technology in the field of corrosion control of the separator plate in order to extend the useful lifetime of the construction materials to the project goal of 40,000 hours

  12. Investigations on autothermal reforming of kerosene Jet A-1 for supplying solid oxide fuel cells (SOFC); Untersuchungen zur autothermen Reformierung von Kerosin Jet A-1 zur Versorgung oxidkeramischer Festelektrolyt-Brennstoffzellen (SOFC)

    Energy Technology Data Exchange (ETDEWEB)

    Lenz, B.

    2007-01-25

    The auxiliary power unit of commercial aircraft is a gas turbine producing electric power with an efficiency of 18 %. This APU can be replaced by a fuel cell system, consisting of an autothermal kerosene reformer and a solid oxide fuel cell (SOFC). The fuel is kerosene Jet A-1. The autothermal reforming of Jet A-1 is practically investigated under variation of steam-to-carbon-ratio, air ratio, space velocity, time in operation and reactor pressure on commercial catalysts. Using stationary system simulation the thermodynamic processes of the device is investigated. Finally, the autothermal reformer and the SOFC consisting of 14 cells are coupled. During this test series, I-V-characteristics are measured, fuel utilisation is calculated and the self-sufficient system operation is shown. (orig.)

  13. On direct internal methane steam reforming kinetics in operating solid oxide fuel cells with nickel-ceria anodes

    Science.gov (United States)

    Thallam Thattai, A.; van Biert, L.; Aravind, P. V.

    2017-12-01

    Major operating challenges remain to safely operate methane fuelled solid oxide fuel cells due to undesirable temperature gradients across the porous anode and carbon deposition. This article presents an experimental study on methane steam reforming (MSR) global kinetics for single operating SOFCs with Ni-GDC (gadolinium doped ceria) anodes for low steam to carbon (S/C) ratios and moderate current densities. The study points out the hitherto insufficient research on MSR global and intrinsic kinetics for operating SOFCs with complete Ni-ceria anodes. Further, it emphasizes the need to develop readily applicable global kinetic models as a subsequent step from previously reported state-of-art and complex intrinsic models. Two rate expressions of the Power law (PL) and Langmuir-Hinshelwood (LH) type have been compared and based on the analysis, limitations of using previously proposed rate expressions for Ni catalytic beds to study MSR kinetics for complete cermet anodes have been identified. Firstly, it has been shown that methane reforming on metallic (Ni) current collectors may not be always negligible, contrary to literature reports. Both PL and LH kinetic models predict significantly different local MSR reaction rate and species partial pressure distributions along the normalized reactor length, indicating a strong need for further experimental verifications.

  14. The economic consequences of a fuel levy reform in South Africa

    Directory of Open Access Journals (Sweden)

    Ramos Mabugu

    2011-06-01

    Full Text Available This paper assesses the economic effects of a hypothetical fuel levy imposed by South African provinces. The welfare effects of increasing the fuel levy by 10 per cent are negative but very small. Similarly, the marginal excess burdens for efficiency and equity (poverty are quite low, suggesting much smaller impacts of the intervention on both economic activity and equity.  Furthermore, a fiscal policy reform that raises fuel levy by 10 per cent is progressive as it has stronger negative effects on higher income households than the lower income households. A potential source of instability for the macroeconomy and total government revenue is the negative effect on economic activity induced by the fuel levy increase. The remedies suggested are that policymakers should make tax room elsewhere in the intergovernmental fiscal system to accommodate the fuel levy increase.

  15. Biogas reforming over multi walled carbon nanotubes with Co-Mo/MgO nanoparticles

    Science.gov (United States)

    Khavarian, Mehrnoush; Mohamed, Abdul Rahman

    2017-12-01

    The utilization of biogas for the production of valuable chemicals is among the very important processes in the energy research field. The most suitable process for biogas reforming is dry reforming of methane. An obvious drawback is the variable composition of biogas rather than the stoichiometrically equimolar quantities of methane and carbon dioxide. Moreover, activating the methane and carbon dioxide molecules in the reforming reaction provides many challenges in exploring new concepts and opportunities for development of unique catalysts. In the present work, the catalytic activity behavior of Co-Mo-MgO/multi-walled carbon nanotubes (MWCNTs) nanocomposite in dry reforming was investigated with different CO2/CH4 feed ratio to evaluate the performance of this catalyst for biogas reforming reaction. It was found that conversions of methane and carbon dioxide were greatly influenced by the feed gas ratio. The CH4 and CO2 conversions are 83 % and 87 % at the reaction temperature of 825 °C, GHSV of 175 L/h.gcat and CO2/CH4 feed ratio of unity. The minimum carbon deposition rate is observed at the CO2/CH4 feed ratio of 0.6 which is 0.080 gc/gcat-h.

  16. Simulated coal-gas fueled carbonate fuel cell power plant system verification. Final report, September 1990--June 1995

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-03-01

    This report summarizes work performed under U.S. Department of Energy, Morgantown Energy Technology Center (DOE/METC) Contract DE-AC-90MC27168 for September 1990 through March 1995. Energy Research Corporation (ERC), with support from DOE, EPRI, and utilities, has been developing a carbonate fuel cell technology. ERC`s design is a unique direct fuel cell (DFC) which does not need an external fuel reformer. An alliance was formed with a representative group of utilities and, with their input, a commercial entry product was chosen. The first 2 MW demonstration unit was planned and construction begun at Santa Clara, CA. A conceptual design of a 10OMW-Class dual fuel power plant was developed; economics of natural gas versus coal gas use were analyzed. A facility was set up to manufacture 2 MW/yr of carbonate fuel cell stacks. A 100kW-Class subscale power plant was built and several stacks were tested. This power plant has achieved an efficiency of {approximately}50% (LHV) from pipeline natural gas to direct current electricity conversion. Over 6,000 hours of operation including 5,000 cumulative hours of stack operation were demonstrated. One stack was operated on natural gas at 130 kW, which is the highest carbonate fuel cell power produced to date, at 74% fuel utilization, with excellent performance distribution across the stack. In parallel, carbonate fuel cell performance has been improved, component materials have been proven stable with lifetimes projected to 40,000 hours. Matrix strength, electrolyte distribution, and cell decay rate have been improved. Major progress has been achieved in lowering stack cost.

  17. International trade and carbon emissions: The role of Chinese institutional and policy reforms.

    Science.gov (United States)

    Andersson, Fredrik N G

    2018-01-01

    The carbon dioxide embodied in Chinese exports to developed countries increased rapidly from 1995 to 2008. We test the extent to which institutional reforms in China can explain this increase. We focus on five areas of reforms: trade liberalization, environmental institutions, legal and property rights, institutional risk and exchange rate policy. Our results show that trade liberalization, weak environmental institutions, exchange rate policy, and legal and property rights affect emissions. Our results also indicate that the lack of reform in the utilities sector is an important factor in the rapid increase in embodied emissions. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Integrated HT-PEMFC and multi-fuel reformer for micro CHP. Final report

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-01

    The project was initiated in April 2008 and completed by the end of March 2010. The project consortium consisted of: Dantherm Power, Serenergy and Department of Energy Technology at Aalborg University (project manager). The activities were coordinated with the project ''Nordjysk H2FC Center'' funded by the Region of Northern Jutland. A number of experimental characterization methods were developed through this project to improve the understanding in fuel cell performance under different operating conditions. In particular the application of Electrochemical Impedance Spectroscopy was found useful and lead to new information about individual losses in the fuel cell. Techniques to measure local temperatures of the MEA were also successfully developed. Durability studies were made on single cells as well as complete stacks. A dedicated test facility was constructed in a container to isolate the test from disturbances that occur in the laboratory. The stack tests were run for just above 6 months with few interruptions and it was found that single cell and stack degradation rates were comparable. Operation temperature was found to have the most pronounced influence on degradation. The information formed the basis for a simple modeling tool to optimize the stack operating temperature versus reformate gas CO concentration. The activities on multi-fuel reformer development were mostly focused on two issues; manufacturability and analyses of flow distribution and heat transfer. The latter was required since these areas these turned out to cause challenges in the reactor design. Through a combination of experimental tests, CFD analyses and flow network modeling design modifications were suggested to improve flow distribution on both the flue gas side and the reformate side. Most of these design changes were not validated in this project through the construction and test of a new reformer. In spite of the problems identifies, the reformed successfully

  19. Major design issues of molten carbonate fuel cell power generation unit

    Energy Technology Data Exchange (ETDEWEB)

    Chen, T.P.

    1996-04-01

    In addition to the stack, a fuel cell power generation unit requires fuel desulfurization and reforming, fuel and oxidant preheating, process heat removal, waste heat recovery, steam generation, oxidant supply, power conditioning, water supply and treatment, purge gas supply, instrument air supply, and system control. These support facilities add considerable cost and system complexity. Bechtel, as a system integrator of M-C Power`s molten carbonate fuel cell development team, has spent substantial effort to simplify and minimize these supporting facilities to meet cost and reliability goals for commercialization. Similiar to other fuels cells, MCFC faces design challenge of how to comply with codes and standards, achieve high efficiency and part load performance, and meanwhile minimize utility requirements, weight, plot area, and cost. However, MCFC has several unique design issues due to its high operating temperature, use of molten electrolyte, and the requirement of CO2 recycle.

  20. Fuel upgrading and reforming with metal organic framework

    KAUST Repository

    Eddaoudi, Mohamed

    2016-03-31

    Systems and methods for separating hydrocarbons on an internal combustion powered vehicle via one or more metal organic frameworks are disclosed. Systems and methods can further include utilizing separated hydrocarbons and exhaust to generate hydrogen gas for use as fuel. In one aspect, a method for separating hydrocarbons can include contacting a first component containing a first metal organic framework with a flow of hydrocarbons and separating hydrocarbons by size. In certain embodiments, the hydrocarbons can include alkanes.

  1. 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

  2. Thermodynamic performance analysis of a fuel cell trigeneration system integrated with solar-assisted methanol reforming

    International Nuclear Information System (INIS)

    Wang, Jiangjiang; Wu, Jing; Xu, Zilong; Li, Meng

    2017-01-01

    Highlights: • Propose a fuel cell trigeneration system integrated with solar-assisted methanol reforming. • Optimize the reaction parameters of methanol steam reforming. • Present the energy and exergy analysis under design and off-design work conditions. • Analyze the contributions of solar energy to the trigeneration system. - Abstract: A solar-assisted trigeneration system for producing electricity, cooling, and heating simultaneously is an alternative scheme to improve energy efficiency and boost renewable energy. This paper proposes a phosphoric acid fuel cell trigeneration system integrated with methanol and steam reforming assisted by solar thermal energy. The trigeneration system consists of a solar heat collection subsystem, methanol steam reforming subsystem, fuel cell power generation subsystem, and recovered heat utilization subsystem. Their respective thermodynamic models are constructed to simulate the system input/output characteristics, and energy and exergy efficiencies are employed to evaluate the system thermodynamic performances. The contribution of solar energy to the system is analyzed using solar energy/exergy share. Through the simulation and analysis of methanol and steam reforming reactions, the optimal reaction pressure, temperature, and methanol to water ratio are obtained to improve the flow rate and content of produced hydrogen. The thermodynamic simulations of the trigeneration system show that the system energy efficiencies at the summer and winter design work conditions are 73.7% and 51.7%, while its exergy efficiencies are 18.8% and 26.1%, respectively. When the solar radiation intensity is different from the design work condition, the total energy and exergy efficiencies in winter decrease approximately by 4.7% and 2.2%, respectively, due to the decrease in solar heat collection efficiency. This proposed novel trigeneration system complemented by solar heat energy and methanol chemical energy is favorable for improving the

  3. Performance and endurance of a PEMFC operated with synthetic reformate fuel feed

    Energy Technology Data Exchange (ETDEWEB)

    Sishtla, C; Koncar, G; Platon, R [Institute of Gas Technology, Des Plaines, IL (United States); Gamburzev, S; Appleby, A J [Texas Engineering Experimental Station, Texas A and M Univ. System, College Station, TX (United States). Center for Electrochemical Systems and Hydrogen Research; Velev, O A [AeroVironment, Inc., Monrovia, CA (United States)

    1998-03-15

    Widespread implementation of polymer electrolyte membrane fuel cell (PEMFC) powerplants for stationary and vehicular applications will be dependent in the near future on using readily available hydrocarbon fuels as the source of the hydrogen fuel. Methane and propane are ideal fuels for stationary applications, while methanol, gasoline, and diesel fuel are better suited for vehicular applications. Various means of fuel processing are possible to produce a gaseous fuel containing H{sub 2}, CO{sub 2} and CO. CO is a known electrocatalyst poison and must be reduced to low (10`s) ppm levels and CO{sub 2} is said to cause additional polarization effects. Even with no CO in the feed gas a H{sub 2}/CO{sub 2}/H{sub 2}O gas mixture will form some CO. Therefore, as a first step of developing a PEMFC that can operate for thousands of hours using a reformed fuel, we used an anode gas feed of 80% H{sub 2} and 20% CO{sub 2} to simulate the reforming of CH{sub 4}. To investigate the effect of reformate on cell performance and endurance, a single cell with an active area of 58 cm{sup 2} was assembled with a membrane electrode assembly (MEA) furnished by Texas A and M University using IGT`s internally manifolded heat exchange (IMHEX{sup TM}) design configuration. The MEA consisted of a Nafion 112 membrane with anode and cathode Pt catalyst loadings of 0.26 and 1.46 mg/cm{sup 2}, respectively. The cell was set to operate on a synthetic reformate - air at 60 C and 1 atm and demonstrated over 5000 h of endurance with a decay rate of less than 1%/1000 h of operation. The cell also underwent four successful thermal cycles with no appreciable loss in performance. The stable performance is attributed to a combination of the IGT IMHEX plate design with its inherent uniform gas flow distribution across the entire active area and MEA quality. The effects of temperature, gas composition, fuel utilization (stoics) and thermal cycle on cell performance are described. (orig.)

  4. Thermal Modeling and Management of Solid Oxide Fuel Cells Operating with Internally Reformed Methane

    Science.gov (United States)

    Wu, Yiyang; Shi, Yixiang; Cai, Ningsheng; Ni, Meng

    2018-06-01

    A detailed three-dimensional mechanistic model of a large-scale solid oxide fuel cell (SOFC) unit running on partially pre-reformed methane is developed. The model considers the coupling effects of chemical and electrochemical reactions, mass transport, momentum and heat transfer in the SOFC unit. After model validation, parametric simulations are conducted to investigate how the methane pre-reforming ratio affects the transport and electrochemistry of the SOFC unit. It is found that the methane steam reforming reaction has a "smoothing effect", which can achieve more uniform distributions of gas compositions, current density and temperature among the cell plane. In the case of 1500 W/m2 power density output, adding 20% methane absorbs 50% of internal heat production inside the cell, reduces the maximum temperature difference inside the cell from 70 K to 22 K and reduces the cathode air supply by 75%, compared to the condition of completely pre-reforming of methane. Under specific operating conditions, the pre-reforming ratio of methane has an optimal range for obtaining a good temperature distribution and good cell performance.

  5. Carbon-based Fuel Cell. Final report

    International Nuclear Information System (INIS)

    Steven S. C. Chuang

    2005-01-01

    The direct use of coal in the solid oxide fuel cell to generate electricity is an innovative concept for power generation. The C-fuel cell (carbon-based fuel cell) could offer significant advantages: (1) minimization of NOx emissions due to its operating temperature range of 700-1000 C, (2) high overall efficiency because of the direct conversion of coal to CO 2 , and (3) the production of a nearly pure CO 2 exhaust stream for the direct CO 2 sequestration. The objective of this project is to determine the technical feasibility of using a highly active anode catalyst in a solid oxide fuel for the direct electrochemical oxidation of coal to produce electricity. Results of this study showed that the electric power generation from Ohio No 5 coal (Lower Kittanning) Seam, Mahoning County, is higher than those of coal gas and pure methane on a solid oxide fuel cell assembly with a promoted metal anode catalyst at 950 C. Further study is needed to test the long term activity, selectivity, and stability of anode catalysts

  6. High-Temperature Desulfurization of Heavy Fuel-Derived Reformate Gas Streams for SOFC Applications

    Science.gov (United States)

    Flytzani-Stephanopoulos, Maria; Surgenor, Angela D.

    2007-01-01

    Desulfurization of the hot reformate gas produced by catalytic partial oxidation or autothermal reforming of heavy fuels, such as JP-8 and jet fuels, is required prior to using the gas in a solid oxide fuel cell (SOFC). Development of suitable sorbent materials involves the identification of sorbents with favorable sulfidation equilibria, good kinetics, and high structural stability and regenerability at the SOFC operating temperatures (650 to 800 C). Over the last two decades, a major barrier to the development of regenerable desulfurization sorbents has been the gradual loss of sorbent performance in cyclic sulfidation and regeneration at such high temperatures. Mixed oxide compositions based on ceria were examined in this work as regenerable sorbents in simulated reformate gas mixtures and temperatures greater than 650 C. Regeneration was carried out with dilute oxygen streams. We have shown that under oxidative regeneration conditions, high regeneration space velocities (greater than 80,000 h(sup -1)) can be used to suppress sulfate formation and shorten the total time required for sorbent regeneration. A major finding of this work is that the surface of ceria and lanthanan sorbents can be sulfided and regenerated completely, independent of the underlying bulk sorbent. This is due to reversible adsorption of H2S on the surface of these sorbents even at temperatures as high as 800 C. La-rich cerium oxide formulations are excellent for application to regenerative H2S removal from reformate gas streams at 650 to 800 C. These results create new opportunities for compact sorber/regenerator reactor designs to meet the requirements of solid oxide fuel cell systems at any scale.

  7. Internal steam reforming in solid oxide fuel cells: Status and opportunities of kinetic studies and their impact on modelling

    DEFF Research Database (Denmark)

    Mogensen, David; Grunwaldt, J.-D.; Hendriksen, Peter Vang

    2011-01-01

    Solid oxide fuel cells (SOFC) systems with internal steam reforming have the potential to become an economically competitive technology for cogeneration power plants, exploiting its significantly higher electrical efficiency compared to existing technologies. Optimal design and operation of such ......Solid oxide fuel cells (SOFC) systems with internal steam reforming have the potential to become an economically competitive technology for cogeneration power plants, exploiting its significantly higher electrical efficiency compared to existing technologies. Optimal design and operation...

  8. MOLTEN CARBONATE FUEL CELL PRODUCT DESIGN IMPROVEMENT

    Energy Technology Data Exchange (ETDEWEB)

    H.C. Maru; M. Farooque

    2005-03-01

    The program was designed to advance the carbonate fuel cell technology from full-size proof-of-concept field test to the commercial design. DOE has been funding Direct FuelCell{reg_sign} (DFC{reg_sign}) development at FuelCell Energy, Inc. (FCE, formerly Energy Research Corporation) from an early state of development for stationary power plant applications. The current program efforts were focused on technology and system development, and cost reduction, leading to commercial design development and prototype system field trials. FCE, in Danbury, CT, is a world-recognized leader for the development and commercialization of high efficiency fuel cells that can generate clean electricity at power stations, or at distributed locations near the customers such as hospitals, schools, universities, hotels and other commercial and industrial applications. FCE has designed three different fuel cell power plant models (DFC300A, DFC1500 and DFC3000). FCE's power plants are based on its patented DFC{reg_sign} technology, where a hydrocarbon fuel is directly fed to the fuel cell and hydrogen is generated internally. These power plants offer significant advantages compared to the existing power generation technologies--higher fuel efficiency, significantly lower emissions, quieter operation, flexible siting and permitting requirements, scalability and potentially lower operating costs. Also, the exhaust heat by-product can be used for cogeneration applications such as high-pressure steam, district heating and air conditioning. Several sub-MW power plants based on the DFC design are currently operating in Europe, Japan and the US. Several one-megawatt power plant design was verified by operation on natural gas at FCE. This plant is currently installed at a customer site in King County, WA under another US government program and is currently in operation. Because hydrogen is generated directly within the fuel cell module from readily available fuels such as natural gas and

  9. Direct ethanol solid oxide fuel cell operating in gradual internal reforming

    Science.gov (United States)

    Nobrega, S. D.; Galesco, M. V.; Girona, K.; de Florio, D. Z.; Steil, M. C.; Georges, S.; Fonseca, F. C.

    2012-09-01

    An electrolyte supported solid oxide fuel cell (SOFC) using standard electrodes, doped-lanthanum manganite cathode and Ni-cermet anode, was operated with direct (anhydrous) ethanol for more than 100 h, delivering essentially the same power output as running on hydrogen. A ceria-based layer provides the catalytic activity for the gradual internal reforming, which uses the steam formed by the electrochemical oxidation of hydrogen for the decomposition of ethanol. Such a concept opens up the way for multi-fuel SOFCs using standard components and a catalytic layer.

  10. Fuel choice, nuclear energy, climate and carbon

    International Nuclear Information System (INIS)

    Shpyth, A.

    2012-01-01

    For the second time since the start of commercial nuclear electricity generation, an accident has the world wondering if uranium will be among the future fuel choices in electricity production. Unfortunate when one considers the low-carbon footprint of this energy option. An accident involving a nuclear power plant, or more appropriately the perceived risks associated with an accident at a nuclear power plant, is but one of the issues that makes the impact assessment process related to nuclear energy projects challenging. Other aspects, including the time scales associated with their siting, licensing, operation and decommissioning, also contribute to the challenge. Strategic environmental assessments for future fuel choices in electricity generation, particularly ones that consider the use of life cycle assessment information, would allow for the effective evaluation of the issues identified above. But more importantly from an impact assessment perspective, provide for a comparative assertion for public disclosure on the environmental impacts of fuel choice. This would provide the public and government decision makers with a more complete view of the role nuclear energy may be able to play in mitigating the climate and carbon impacts of increased electricity production, and place issues of cost, complexity and scale in a more understandable context.

  11. Control and Experimental Characterization of a Methanol Reformer for a 350 W High Temperature Polymer Electrolyte Membrane Fuel Cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    , i.e. cathode and anode gas flows and temperature by using mass flow controllers and controlled heaters. Using this system the methanol reformer is characterized in its different operating points, both steady-state but also dynamically. Methanol steam reforming is a well known process, and provides...... and burner and the behaviour of the CO concentration of the reformate gas....... the high temperature waste gas from a cathode air cooled 45 cell HTPEM fuel cell stack. The MEAs used are BASF P2100 which use phosphoric acid doped polybenzimidazole type membranes; an MEA with high CO tolerance and no complex humidity requirements. The methanol reformer used is integrated into a compact...

  12. 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

    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/steam and refor......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....../steam fuel split into two processes with opposing temperature behavior in the reformate fuels. An 87.5% reduction in active electrode area diminishes the gas conversion impedance in the hydrogen/steam fuel at high fuel flow rates. In both reformates, the second and third lowest frequency processes merged...

  13. Design and Control of High Temperature PEM Fuel Cell Systems using Methanol Reformers with Air or Liquid Heat Integration

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Sahlin, Simon Lennart

    2013-01-01

    The present work describes the ongoing development of high temperature PEM fuel cell systems fuelled by steam reformed methanol. Various fuel cell system solutions exist, they mainly differ depending on the desired fuel used. High temperature PEM (HTPEM) fuel cells offer the possibility of using...... methanol is converted to a hydrogen rich gas with CO2 trace amounts of CO, the increased operating temperatures allow the fuel cell to tolerate much higher CO concentrations than Nafion-based membranes. The increased tolerance to CO also enables the use of reformer systems with less hydrogen cleaning steps...... liquid fuels such as methanol, due to the increased robustness of operating at higher temperatures (160-180oC). Using liquid fuels such as methanol removes the high volume demands of compressed hydrogen storages, simplifies refueling, and enables the use of existing fuel distribution systems. The liquid...

  14. Carbonization plant for low temperature carbonization of solid fuels

    Energy Technology Data Exchange (ETDEWEB)

    1948-02-13

    A carbonization plant for the low-temperature carbonization of solid fuels, consists of a heat-treating retort including an outer vertical stationary tube, a second inner tube coaxial with the first tube, adapted to rotate round its axis and defining the first tube, and an annular gap where the solid fuel is treated. The inside of the inner tube is divided in two parts, the first fed with superheated steam which is introduced into the annular gap through vents provided in the wall of the inner tube, the second part communicating with the gap by means of vents provided in the wall of the inner tube through which gases and oil vapors evolved from the fuel are evacuated. A combustion furnace is provided in which the hot solid residues evacuated at the bottom of the annular gap are burned and from which hot fumes are evacuated, a conduit surrounding, in the form of a helical flue, outer cylinder of the retort, and in which flow hot fumes; a preliminary drier for the raw solid fuel heated by the whole or a part of the fumes evacuated from the combustion furnace. Means for bringing solid fuels from the outlet of the preliminary drier to the upper inlet of the gap of the retort a pipe line receiving steam and bringing it into the first inside part of the inner tube, this pipe line has portions located within the conduit for the fumes in order to superheat the steam, and an expansion chamber in which the gases and oil vapors are trapped at the bottom of the second inside part of the inner tube are included.

  15. Climate consequences of low-carbon fuels: The United States Renewable Fuel Standard

    International Nuclear Information System (INIS)

    Hill, Jason; Tajibaeva, Liaila; Polasky, Stephen

    2016-01-01

    A common strategy for reducing greenhouse gas (GHG) emissions from energy use is to increase the supply of low-carbon alternatives. However, increasing supply tends to lower energy prices, which encourages additional fuel consumption. This “fuel market rebound effect” can undermine climate change mitigation strategies, even to the point where efforts to reduce GHG emissions by increasing the supply of low-carbon fuels may actually result in increased GHG emissions. Here, we explore how policies that encourage the production of low-carbon fuels may result in increased GHG emissions because the resulting increase in energy use overwhelms the benefits of reduced carbon intensity. We describe how climate change mitigation strategies should follow a simple rule: a low-carbon fuel with a carbon intensity of X% that of a fossil fuel must displace at least X% of that fossil fuel to reduce overall GHG emissions. We apply this rule to the United States Renewable Fuel Standard (RFS2). We show that absent consideration of the fuel market rebound effect, RFS2 appears to reduce GHG emissions, but once the fuel market rebound effect is factored in, RFS2 actually increases GHG emissions when all fuel GHG intensity targets are met. - Highlights: • Low-carbon fuels partially displace petroleum via fuel market rebound effect. • Synthesis of recent analyses shows incomplete petroleum displacement by biofuels. • Fuel market rebound effect can reduce or reverse climate benefit of low-carbon fuels. • Fossil fuel displacement must exceed relative carbon footprint of a low-carbon fuel. • The Renewable Fuel Standard increases greenhouse gas emissions when mandate is met.

  16. Session 4: The influence of elementary heterogeneous reforming chemistry within solid-oxide fuel cell anodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, H.; Kee, R.J. [Engineering Division, Colorado School of Mines, Golden, CO (United States); Janardhanan, V.M.; Deutschmann, O. [Karlsruhe Univ., Institute for Chemical Technology (Germany); Goodwin, D.G. [Engineering and Applied Science., California Inst. of Technology, Pasadena, CA (United States); Sullivan, N.P. [ITN Energy Systems, Littleton, CO (United States)

    2004-07-01

    In the work presented a computational model is developed that represents the coupled effects of fluid flow in fuel channels, porous media transport and chemistry in the anode, and electrochemistry associated with the membrane-electrode assembly. An important objective is to explore the role of heterogeneous chemistry within the anode. In addition to cell electrical performance the chemistry model predicts important behaviors like catalyst-fouling deposit formation (i.e., coking). The model is applied to investigate alternative fuel-cell operating conditions, including varying fuel flow rates, adding air to the fuel stream, and recirculating exhaust gases. Results include assessments of performance metrics like fuel utilization, cell efficiency, power density, and catalyst coking. The model shows that 'direct electrochemical oxidation' of hydrocarbon fuels in solid-oxide fuel cells can be explained by a process that involves reforming the fuel to H{sub 2}, with hydrogen being the only species responsible for charge exchange. The model can be applied to investigate alternative design and operating conditions, seeking to improve the overall performance. (O.M.)

  17. Use of catalytic reforming to aid natural gas HCCI combustion in engines: experimental and modelling results of open-loop fuel reforming

    Energy Technology Data Exchange (ETDEWEB)

    Peucheret, S.; Wyszynski, M.L.; Lehrle, R.S. [Future Power Systems Group, Mechanical Engineering, The University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Golunski, S. [Johnson Matthey, Technology Centre, Blount' s Court, Sonning Common, Reading RG4 9NH (United Kingdom); Xu, H. [Jaguar Land Rover Research, Jaguar Land Rover W/2/021, Abbey Road, Coventry CV3 4LF (United Kingdom)

    2005-12-01

    The potential of the homogeneous charge compression ignition (HCCI) combustion process to deliver drastically reduced emissions of NO{sub x} and improved fuel economy from internal combustion engines is well known. The process is, however, difficult to initiate and control, especially when methane or natural gas are used as fuel. To aid the HCCI combustion of natural gas, hydrogen addition has been successfully used in this study. This hydrogen can be obtained from on-line reforming of natural gas. Methane reforming is achieved here by reaction with engine exhaust gas and air in a small scale monolith catalytic reactor. The benchmark quantity of H{sub 2} required to enhance the feasibility and engine load range of HCCI combustion is 10%. For low temperature engine exhaust gas, typical for HCCI engine operating conditions, experiments show that additional air is needed to produce this quantity. Experimental results from an open-loop fuel exhaust gas reforming system are compared with two different models of basic thermodynamic equilibria calculations. At the low reactor inlet temperatures needed for the HCCI application (approx. 400 deg C) the simplified three-reaction thermodynamic equilibrium model is in broad agreement with experimental results, while for medium (550-650 deg C) inlet temperature reforming with extra air added, the high hydrogen yields predicted from the multi-component equilibrium model are difficult to achieve in a practical reformer. (author)

  18. A novel reactor type for autothermal reforming of diesel fuel and kerosene

    International Nuclear Information System (INIS)

    Pasel, Joachim; Samsun, Remzi Can; Tschauder, Andreas; Peters, Ralf; Stolten, Detlef

    2015-01-01

    Highlights: • Development and experimental evaluation of Juelich’s novel ATR reactor type. • Constructive integration of steam generation chamber and nozzle for water injection. • Internal steam generator modified to reduce pressure drop to approx. a thirtieth. • Novel concept for ATR heat management proven to be suitable for fuel cell systems. • Reaction conditions during shut-down and start-up optimized to reduce byproducts. - Abstract: This paper describes the development and experimental evaluation of Juelich’s novel reactor type ATR AH2 for autothermal reforming of diesel fuel and kerosene. ATR AH2 overcomes the disadvantages of Juelich’s former reactor generations from the perspective of the fuel cell system by constructively integrating an additional pressure swirl nozzle for the injection of cold water and a steam generation chamber. As a consequence, ATR AH2 eliminates the need for external process configurations for steam supply. Additionally, the internal steam generator has been modified by increasing its cross-sectional area and by decreasing its length. This measure reduces the pressure drop of the steam generator from approx. 500 mbar to roughly a thirtieth. The experimental evaluation of ATR AH2 at steady state revealed that the novel concept for heat management applied in ATR AH2 is suitable for fuel cell systems at any reformer load point between 20% and 120% when the mass fractions of cold water to the newly integrated nozzle are set to values between 40% and 50%. The experimental evaluation of ATR AH2 during start-up and shut-down showed that slight modifications of the reaction conditions during these transient phases greatly reduced the concentrations of ethene, ethane, propene and benzene in the reformate. From the fuel cell system perspective, these improvements provide a very beneficial contribution to longer stabilities for the catalysts and adsorption materials

  19. Steam and partial oxidation reforming options for hydrogen production from fossil fuels for PEM fuel cells

    OpenAIRE

    Yousri M.A. Welaya; Mohamed M. El Gohary; Nader R. Ammar

    2012-01-01

    Proton exchange membrane fuel cell (PEM) generates electrical power from air and from hydrogen or hydrogen rich gas mixtures. Therefore, there is an increasing interest in converting current hydrocarbon based marine fuels such as natural gas, gasoline, and diesel into hydrogen rich gases acceptable to the PEM fuel cells on board ships. Using chemical flow sheeting software, the total system efficiency has been calculated. Natural gas appears to be the best fuel for hydrogen rich gas productio...

  20. Draft, development and optimization of a fuel cell system for residential power generation with steam reformer; Entwurf, Aufbau und Optimierung eines PEM-Brennstoffzellensystems zur Hausenergieversorgung mit Dampfreformer

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, H

    2006-05-17

    The first development cycle of a residential power generation system is described. A steam reformer was chosen to produce hydrogen out of natural gas. After carbon monoxide purification with a preferential oxidation (PrOx) unit the hydrogen rich reformat gas is feed to the anode of the PEM-fuel cell, where due to the internal reaction with air oxygen form the cathode side water, heat and electricity is produced. Due to an incomplete conversion the anode off gas contains hydrogen and residual methane, which is feed to the burner of the steam reformer to reduce the needed amount of external fuel to heat the steam reformer. To develop the system the components are separately investigated and optimized in their construction or operation to meet the system requirements. After steady state and dynamic characterization of the components they were coupled one after another to build the system. To operate the system a system control was developed to operate and characterize this complex system. After characterization the system was analyzed for further optimization. During the development of the system inventions like a water cooled PrOx, an independent fuel cell controller or a burner for anodic off gas recirculation were made. The work gives a look into the interactions between the components and allows to understand the problems by coupling such components. (orig.)

  1. Modeling and control of the output current of a Reformed Methanol Fuel Cell system

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Pasupathi, Sivakumar

    2015-01-01

    In this work, a dynamic Matlab SIMULINK model of the relationship between the fuel cell current set point of a Reformed Methanol Fuel Cell system and the output current of the system is developed. The model contains an estimated fuel cell model, based on a polarization curve and assumed first order...... dynamics, as well as a battery model based on an equivalent circuit model and a balance of plant power consumption model. The models are tuned with experimental data and verified using a verification data set. The model is used to develop an output current controller which can control the charge current...... of the battery. The controller is a PI controller with feedforward and anti-windup. The performance of the controller is tested and verified on the physical system....

  2. The battle of the fuel cell. De slag om de brandstofcel

    Energy Technology Data Exchange (ETDEWEB)

    Van Dijkum, P H [Nederlandse Organisatie voor Energie en Milieu BV (NOVEM), Sittard (Netherlands)

    1992-03-01

    An overview is given of several types of fuel cells and for each type the international state of the art in the development and technology. The fuel cells discussed are: the alkaline fuel cell (AFC), the proton exchange membrane fuel cell (PEMFC), the phosphoric acid fuel cell (PAFC), the external reforming molten carbonate fuel cell (ER-MCFC), the internal reforming molten carbonate fuel cell (IR-MCFC) and the solid oxide fuel cell (SOFC). 1 figs., 3 ills., 5 tabs., 7 refs.

  3. Carbon-coated ceramic membrane reactor for production of hydrogen via aqueous phase reforming of sorbitol

    NARCIS (Netherlands)

    Neira d'Angelo, M.F.; Ordomskiy, V.; Schouten, J.C.; Schaaf, van der J.; Nijhuis, T.A.

    2014-01-01

    Hydrogen was produced by aqueous-phase reforming (APR) of sorbitol in a carbon-on-alumina tubular membrane reactor (4 nm pore size, 7 cm long, 3 mm internal diameter) that allows the hydrogen gas to permeate to the shell side, whereas the liquid remains in the tube side. The hydrophobic nature of

  4. Preparation and Performance Validation of Nano-Perovskite Type for Carbon Dioxide Reforming of Methane.

    Science.gov (United States)

    Kim, Taegyu; Park, Daeil

    2018-02-01

    This paper describes the La0.8Sr0.2NiO3 perovskite-type catalysts supported on α-Al2O3 that were prepared by polyol method and used as a catalyst for the carbon dioxide reforming of methane. The effect of the molar concentration of polyvinyl-pyrrolidone (PVP) on the reducibility, structural properties and carbon deposition was characterized by XRD, and TGA. The carbon dioxide reforming of methane on the catalyst was performed at the different concentration of PVP. At the 1 M PVP, main characteristic peaks of perovskite structure were established without impurities, thus showing the highest catalytic activity; 87.7% and 92.1% in CH4 and CO2 conversion, respectively. After the reaction, carbon deposition was 0.4-0.6%, while 6.2% on the existing Ni catalyst, indicating the perovskite-type catalyst has a superior characteristic preventing it from the carbon deposition at the carbon dioxide reforming of methane.

  5. Experimental Evaluation of a Pt-based Heat Exchanger Methanol Reformer for a HTPEM Fuel Cell Stack

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Nielsen, Mads Pagh

    2008-01-01

    and automotive applications. Using a liquid hydrocarbon as e.g. methanol as the hydrogen carrier and reforming it to a hydrogen rich gas can solve some of these storage issues. The work presented here examines the use of a heat exchanger methanol reformer for use with a HTPEM fuel cell stack. Initial......Fuel cell systems running on pure hydrogen can efficiently produce electricity and heat for various applications, stationary and mobile. Storage volume can be problematic for stationary fuel cell systems with high run-time demands, but it is especially a challenge when dealing with mobile...

  6. Carbon dioxide management by chemical conversion to methanol: HYDROGENATION and BI-REFORMING

    International Nuclear Information System (INIS)

    Wiesberg, Igor L.; Medeiros, José Luiz de; Alves, Rita M.B.; Coutinho, Paulo L.A.; Araújo, Ofélia Q.F.

    2016-01-01

    Highlights: • Evaluation of carbon dioxide conversion to methanol by two chemical routes. • HYDROGENATION: conversion via catalytic hydrogenation at high pressure. • BI-REFORMING: conversion via syngas from bi-reforming of natural gas. • HYDROGENATION is viable for hydrogen price inferior to 1000 US$/t. • BI-REFORMING is unable to avoid emissions; viable only if gas price is very low. - Abstract: Chemical conversion of carbon dioxide to methanol has the potential to address two relevant sustainability issues: economically feasible replacement of fossil raw materials and avoidance of greenhouse gas emissions. However, chemical stability of carbon dioxide is a challenging impediment to conversion requiring severe reaction conditions at the expense of increased energy input, therefore adding capital, operation and environmental costs, which could result in partial or total override of its potential sustainability as feedstock to the chemical and energy industries. This work investigates two innovative chemical destinations of carbon dioxide to methanol, namely a direct conversion through carbon dioxide hydrogenation (HYDROGENATION), and an indirect via carbon dioxide conversion to syngas through bi-reforming (BI-REFORMING). Process simulation is used to obtain mass and energy balances needed to support assessment of economic and environmental performance. A business scenario is considered where an industrial source of nearly pure carbon dioxide exists and an investment decision for utilization of carbon dioxide is faced. Due to uncertainties in prices of the raw materials, hydrogen (HYDROGENATION) and natural gas (BI-REFORMING), the decision procedure includes the definition of price thresholds to reach profitability. Sensitivity analyses are performed varying costs with greater uncertainty, i.e., carbon dioxide and methanol, and recalculating maximum allowable prices of raw materials. The analyses show that in a Brazilian scenario, BI-REFORMING is unlikely

  7. Exergetic analysis and optimization of a solar-powered reformed methanol fuel cell micro-powerplant

    Science.gov (United States)

    Hotz, Nico; Zimmerman, Raúl; Weinmueller, Christian; Lee, Ming-Tsang; Grigoropoulos, Costas P.; Rosengarten, Gary; Poulikakos, Dimos

    The present study proposes a combination of solar-powered components (two heaters, an evaporator, and a steam reformer) with a proton exchange membrane fuel cell to form a powerplant that converts methanol to electricity. The solar radiation heats up the mass flows of methanol-water mixture and air and sustains the endothermic methanol steam reformer at a sufficient reaction temperature (typically between 220 and 300 °C). In order to compare the different types of energy (thermal, chemical, and electrical), an exergetic analysis is applied to the entire system, considering only the useful part of energy that can be converted to work. The effect of the solar radiation intensity and of different operational and geometrical parameters like the total inlet flow rate of methanol-water mixture, the size of the fuel cell, and the cell voltage on the performance of the entire system is investigated. The total exergetic efficiency comparing the electrical power output with the exergy input in form of chemical and solar exergy reaches values of up to 35%, while the exergetic efficiency only accounting for the conversion of chemical fuel to electricity (and neglecting the 'cost-free' solar input) is increased up to 59%. At the same time, an electrical power density per irradiated area of more than 920 W m -2 is obtained for a solar heat flux of 1000 W m -2.

  8. The market effectiveness of electricity reform: A case of carbon emissions trading market of Shenzhen city

    Science.gov (United States)

    Wang, Yongli; Wang, Gang; Zuo, Yi; Fan, Lisha; Xiao, Yao

    2017-03-01

    In the 13th Five-Year Plan, the Chinese government proposed to achieve the national carbon emission trading market established by 2017. The establishment of carbon emission trading market is the most important one in power reform, which helps to promote the power reform and achieve the goal of energy saving and emission reduction. As the bond of connecting environment energy issues and the economic development, carbon emissions trading market has become a hot research topic in the related fields, by market means, it incentive the lower cost subject emissions to undertake more reductions and therefore to benefit, the body of the high cost finished the task by buying quota reduction, to achieve the effect of having the least social total cost. Shenzhen has become the first city in China to start carbon trading pilot formally on June 16, 2013, online trading on June 18. The paper analyzes the market effectiveness of electricity reform in China, which takes carbon emissions trading market of Shenzhen city for example, and gives some suggestions for future development.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kevin Whitty

    2007-06-30

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

  10. Fuel Mix Impacts from Transportation Fuel Carbon Intensity Standards in Multiple Jurisdictions

    Science.gov (United States)

    Witcover, J.

    2017-12-01

    Fuel carbon intensity standards have emerged as an important policy in jurisdictions looking to target transportation greenhouse gas (GHG) emissions for reduction. A carbon intensity standard rates transportation fuels based on analysis of lifecycle GHG emissions, and uses a system of deficits and tradable, bankable credits to reward increased use of fuels with lower carbon intensity ratings while disincentivizing use of fuels with higher carbon intensity ratings such as conventional fossil fuels. Jurisdictions with carbon intensity standards now in effect include California, Oregon, and British Columbia, all requiring 10% reductions in carbon intensity of the transport fuel pool over a 10-year period. The states and province have committed to grow demand for low carbon fuels in the region as part of collaboration on climate change policies. Canada is developing a carbon intensity standard with broader coverage, for fuels used in transport, industry, and buildings. This study shows a changing fuel mix in affected jurisdictions under the policy in terms of shifting contribution of transportation energy from alternative fuels and trends in shares of particular fuel pathways. It contrasts program designs across the jurisdictions with the policy, highlights the opportunities and challenges these pose for the alternative fuel market, and discusses the impact of having multiple policies alongside federal renewable fuel standards and sometimes local carbon pricing regimes. The results show how the market has responded thus far to a policy that incentivizes carbon saving anywhere along the supply chain at lowest cost, in ways that diverged from a priori policy expectations. Lessons for the policies moving forward are discussed.

  11. Fiscal reform of fuel regulation in Brazil: recent developments and environmental implications

    Energy Technology Data Exchange (ETDEWEB)

    Hinostroza, Miriam; Sauer, Ildo Luis; Guerra, Sinclair M.-G.

    2005-11-15

    Internationally the fossil fuel-based energy sector now faces increasing uncertainties due to changes in its fiscal regulation, prompted by pressure for environmental regulation. These changes typically eliminate some taxes at the beginning of the oil production chain, but compensate for these by increasing taxation on consumption. In Brazil, fiscal reform proposals focus not on environmental arguments but on the elimination of excess levies and red tape and on increasing equity across income classes. However, liberalization process of oil and gas industries in Brazil has led to modifications in fuels taxation. This article discusses current Brazilian fiscal policy as related to fossil fuels, explaining the nature of recently introduced contribution for economic regulation (Contribuicao de Intervencao ao Dominio Economico, CIDE) and the impacts on price formation. It also shows how those modifications tend to include external costs from activities in the fuel sector; through revenues from a levy earmarked for two purposes: i) funding investments in projects deemed to be environmentally beneficial, and, ii) improvements in road infrastructure aimed at reducing emissions from transportation. Some ideas on how to improve use of the levy to perk up fuel alcohol competitiveness are also discussed. (Author)

  12. Upgrading versus reforming: an energy and exergy analysis of two Solid Oxide Fuel Cell-based systems for a convenient biogas-to-electricity conversion

    International Nuclear Information System (INIS)

    Baldinelli, A.; Barelli, L.; Bidini, G.

    2017-01-01

    Highlights: • Biogas-to-electricity conversion through Solid Oxide Fuel Cell is investigated. • Two solutions are compared for biogas-to-electricity conversion. • Direct feeding by partially upgraded biogas meets with fuel cell long operation. • Best energy and exergy performances are obtained with an innovative system-design. • A sensitivity analysis on the process parameters determines its convenience margin. - Abstract: Aiming at designing biogas-to-electricity advanced systems, Solid Oxide Fuel Cells are promising candidates. They benefit from scalability on plant sizes that suit anaerobic digesters potentialities. For biogas-Solid Oxide Fuel Cells applications, the implementation of an external pre-reformer is usually considered. However, the possibility to perform direct fuel feeding to the Solid Oxide Fuel Cell offers new opportunities towards the realization of lean systems, which are competitive especially on small-scale installations (i.e. on-farm biogas-to-electricity conversion). In this frame, scientific literature is rather poor and, to cover this gap, system simulations are called for two reasons: first, to demonstrate the potential efficiency gain of new concepts; second, to provide a meaningful support for long-term experimental investigation on Solid Oxide Fuel Cells operated upon direct feeding of unreformed biogas. For that, the current study compares two system designs for biogas utilization into Solid Oxide Fuel Cells. The conventional one realizes biogas steam reforming prior the fuel cell, while the novel concept is based on direct feeding of partially upgraded biogas by means of carbon dioxide-separation membranes. As main outcome of the study, the system equipped with carbon dioxide-separation membranes achieves better performances than its conventional competitor does, scoring 51.1% energy efficiency and 52.3% exergy efficiency (compared to 37.2% and 38.6% respectively exhibited by the reformer-based system). Because of the lack

  13. Development of a coupled reactor with a catalytic combustor and steam reformer for a 5 kW solid oxide fuel cell system

    International Nuclear Information System (INIS)

    Kang, Sanggyu; Lee, Kanghun; Yu, Sangseok; Lee, Sang Min; Ahn, Kook-Young

    2014-01-01

    Highlights: • Proposes the scale-up strategy to develop a large-scale coupled reactor. • Investigation of performance of steam reformer coupled with catalytic combustor. • Experimental parameters are inlet temp., air excess ratio, SCR, fuel utilization. • Evaluation of the heat transfer distribution along the gas flow direction. • The mean value of methane conversion rate is approximately 93.4%. - Abstract: The methane (CH 4 ) conversion rate of a steam reformer can be increased by thermal integration with a catalytic combustor, called a coupled reactor. In the present study, a 5 kW coupled reactor has been developed based on a 1 kW coupled reactor in previous work. The geometric parameters of the space velocity, diameter and length of the coupled reactor selected from the 1 kW coupled reactor are tuned and applied to the design of the 5 kW coupled reactor. To confirm the scale-up strategy, the performance of 5 kW coupled reactor is experimentally investigated with variations of operating parameters such as the fuel utilization in the solid oxide fuel cell (SOFC) stack, the inlet temperature of the catalytic combustor, the excess air ratio of the catalytic combustor, and the steam to carbon ratio (SCR) in the steam reformer. The temperature distributions of coupled reactors are measured along the gas flow direction. The gas composition at the steam reformer outlet is measured to find the CH 4 conversion rate of the coupled reactor. The maximum value of the CH 4 conversion rate is approximately 93.4%, which means the proposed scale-up strategy can be utilized to develop a large-scale coupled reactor

  14. Fuel moisture influences on fire-altered carbon in masticated fuels: An experimental study

    Science.gov (United States)

    Nolan W. Brewer; Alistair M.S. Smith; Jeffery A. Hatten; Philip E. Higuera; Andrew T. Hudak; Roger D. Ottmar; Wade T. Tinkham

    2013-01-01

    Biomass burning is a significant contributor to atmospheric carbon emissions but may also provide an avenue in which fire-affected ecosystems can accumulate carbon over time, through the generation of highly resistant fire-altered carbon. Identifying how fuel moisture, and subsequent changes in the fire behavior, relates to the production of fire-altered carbon is...

  15. Carbon taxation reform in the European Union. The options involved

    International Nuclear Information System (INIS)

    Laurent, Eloi; Le Cacheux, Jacques

    2011-01-01

    Even though the EU clearly leads the global fight against climate change and despite the additional reduction in emissions due to the global crisis and European recession, the ambitious objectives flagged in the '20-20-20 by 2020' strategy and 'climate-energy package' may be out of reach if a more resolute and consistent policy of carbon taxation is not rapidly put in place in the EU. In this paper, we detail and discuss the different options available for such European carbon taxation. Initially published in 'Revue de l'OFCE' No. 116

  16. Achieving high performance in intermediate temperature direct carbon fuel cells with renewable carbon as a fuel source

    International Nuclear Information System (INIS)

    Hao, Wenbin; He, Xiaojin; Mi, Yongli

    2014-01-01

    Highlights: • Bamboo fiber and waste paper were pyrolyzed to generate bamboo carbon and waste paper carbon as anode fuels of IT-DCFC. • Superior cell performance was achieved with the waste paper carbon. • The results suggested the high performance was due to the highest thermal reactivity and the catalytic inherent impurities. • Calcite and kaolinite as inherent impurities favored the thermal decomposition and the electrooxidation of carbon. - Abstract: Three kinds of carbon sources obtained from carbon black, bamboo fiber and waste paper were investigated as anode fuels in an intermediate temperature direct carbon fuel cell. The carbon sources were characterized with X-ray photoelectron spectroscopy, thermal gravimetric analysis, etc. The results indicated that the waste paper carbon was more abundant in calcite and kaolinite, and showed higher thermal reactivity in the intermediate temperature range compared with the other two carbon sources. The cell performance was tested at 650 °C in a hybrid single cell, using Sm 0.20 Ce 0.80 O 2−x as the electrolyte. As a result, the cell fed with waste paper carbon showed the highest performance among the three carbon sources, with a peak power density of 225 mW cm −2 . The results indicated that its inherent impurities, such as calcite and kaolinite, might favor the thermal gasification of renewable carbon sources, which resulted in the enhanced performance of the intermediate temperature direct carbon fuel cell

  17. Design, fabrication and performance evaluation of an integrated reformed methanol fuel cell for portable use

    Science.gov (United States)

    Zhang, Shubin; Zhang, Yufeng; Chen, Junyu; Yin, Congwen; Liu, Xiaowei

    2018-06-01

    In this paper, an integrated reformed methanol fuel cell (RMFC) as a portable power source is designed, fabricated and tested. The RMFC consists of a methanol steam reformer (MSR), a high temperature proton exchange membrane fuel cell (HT-PEMFC) stack, a microcontroller unit (MCU) and other auxiliaries. First, a system model based on Matlab/Simulink is established to investigate the mass and energy transport characteristics within the whole system. The simulation results suggest a hydrogen flow rate of at least 670 sccm is needed for the system to output 30 W and simultaneously maintain thermal equilibrium. Second, a metallic MSR and an HT-PEMFC stack with 12 cells are fabricated and tested. The tests show that the RMFC system is able to function normally when the performances of all the components meet the minimum requirements. At last, in the experiment of successfully powering a laptop, the RMFC system exhibits a stable performance during the complete work flow of all the phases, namely start-up, output and shutdown. Moreover, with a conservative design of 20 W power rating, maximum energy conversion efficiency of the RMFC system can be achieved (36%), and good stability in long-term operation is shown.

  18. Fuel processor and method for generating hydrogen for fuel cells

    Science.gov (United States)

    Ahmed, Shabbir [Naperville, IL; Lee, Sheldon H. D. [Willowbrook, IL; Carter, John David [Bolingbrook, IL; Krumpelt, Michael [Naperville, IL; Myers, Deborah J [Lisle, IL

    2009-07-21

    A method of producing a H.sub.2 rich gas stream includes supplying an O.sub.2 rich gas, steam, and fuel to an inner reforming zone of a fuel processor that includes a partial oxidation catalyst and a steam reforming catalyst or a combined partial oxidation and stream reforming catalyst. The method also includes contacting the O.sub.2 rich gas, steam, and fuel with the partial oxidation catalyst and the steam reforming catalyst or the combined partial oxidation and stream reforming catalyst in the inner reforming zone to generate a hot reformate stream. The method still further includes cooling the hot reformate stream in a cooling zone to produce a cooled reformate stream. Additionally, the method includes removing sulfur-containing compounds from the cooled reformate stream by contacting the cooled reformate stream with a sulfur removal agent. The method still further includes contacting the cooled reformate stream with a catalyst that converts water and carbon monoxide to carbon dioxide and H.sub.2 in a water-gas-shift zone to produce a final reformate stream in the fuel processor.

  19. 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 necessary to prevent poisoning and thereby to decrease the degradation rate....

  20. A case study of different configurations for the performance analysis of solid oxide fuel cells with external reformers

    International Nuclear Information System (INIS)

    Lee, Kang Hun; Woo, Hyun Tak; Yu, Sang Seok; Lee, Sang Min; Lee, Young Duk; Kang, Sang Gyu; Ahn, Kook Young

    2012-01-01

    A planar solid oxide fuel cell (PSOFC) is studied in its application in a high temperature stationary power plant. Even though PSOFCs with external reformers are designed for application from the distributed power source to the central power plant, such PSOFCs may sacrifice more system efficiency than internally reformed SOFCs. In this study, modeling of the PSOFC with an external reformer was developed to analyze the feasibility of thermal energy utilization for the external reformer. The PSOFC system model includes the stack, reformer, burner, heat exchanger, blower, pump, PID controller, 3-way valve, reactor, mixer, and steam separator. The model was developed under the Matlab/Simulink environment with Thermolib'R'modules. The model was used to study the system performance according to its configuration. Three configurations of the SOFC system were selected for the comparison of the system performance. The system configuration considered the cathode recirculation, thermal sources for the external reformer, heat up of operating gases, and condensate anode off gas for the enhancement of the fuel concentration. The simulation results show that the magnitude of the electric efficiency of the PSOFC system for Case 2 is 12.13% higher than that for Case 1 (reference case), and the thermal efficiency of the PSOFC system for Case 3 is 76.12%, which is the highest of all the cases investigated

  1. Experimental investigations and modeling of direct internal reforming of biogases in tubular solid oxide fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Lanzini, A.; Leone, P.; Pieroni, M.; Santarelli, M. [Dipartimento di Energetica, Politecnico di Torino, Corso Duca degli Abruzzi 24, IT-10129, Torino (Italy); Beretta, D.; Ginocchio, S. [Centro Ricerca e Sviluppo, Edison S.p.a, Via La Pira 2, IT-10028 Trofarello, Torino (Italy)

    2011-10-15

    Biogas-fed Solid Oxide Fuel Cell (SOFC) systems can be considered as interesting integrated systems in the framework of distributed power generation. In particular, bio-methane and bio-hydrogen produced from anaerobic digestion of organic wastes represent renewable carbon-neutral fuels for high efficiency electrochemical generators. With such non-conventional mixtures fed to the anode of the SOFC, the interest lies in understanding the multi-physics phenomena there occurring and optimizing the geometric and operation parameters of the SOFC, while avoiding operating and fuel conditions that can lead to or accelerate degradation processes. In this study, an anode-supported (Ni-YSZ) tubular SOFC was considered; the tubular geometry enables a relatively easy separation of the air and fuel reactants and it allows one to evaluate the temperature field of the fuel gas inside the tube, which is strictly related to the electrochemical and heterogeneous chemical reactions occurring within the anode volume. The experiments have been designed to analyze the behavior of the cell under different load and fuel utilization (FU) conditions, providing efficiency maps for both fuels. The experimental results were used to validate a multi-physics model of the tubular cell. The model showed to be in good agreement with the experimental data, and was used to study the sensitive of some selected geometrical parameters modification over the cell performances. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Evaluation of policy options to reform the EU Emissions Trading System. Effects on carbon price, emissions and the economy

    Energy Technology Data Exchange (ETDEWEB)

    Verdonk, M.; Brink, C.; Vollebergh, H.; Roelfsema, M.

    2013-04-15

    The EU Emissions Trading System (EU ETS) is a key instrument of EU climate policy, providing a clear reduction pathway for CO2 emissions. The current carbon price (of about 3 euros per tonne of CO2, April 2013) is much lower than previously expected (which was around 30 euros) and is likely to remain low for a long time. This fuels doubts about whether the ETS will remain a key policy instrument in the long term. Such doubts also increase investment uncertainty, which is likely to have a negative impact on further investments in low-carbon technologies needed for a low-carbon economy in 2050. In November 2012, the European Commission put forward six options for a more structural reform of the EU ETS. The proposed options vary from reducing the cap and expanding the ETS to include other sectors, to strengthening the ETS by measures directly affecting allowance prices. The Dutch Ministry of Infrastructure and the Environment (IenM) asked the PBL Netherlands Environmental Assessment Agency to assess the impact of these options. Four categories of options for reforming the ETS were evaluated: (1) reducing the supply of emission allowances; (2) expanding the ETS by including other sectors; (3) a minimum price for auctioned allowances; and (4) combining ETS with a carbon tax. Recently, the European Parliament voted against the European Commission's proposal to temporarily set aside emission allowances. In an earlier assessment of this proposal, PBL concluded that the impact of this backloading proposal on CO2 prices is likely to be limited, because the total amount of allowances up to 2020 would remain unchanged. All options analysed would reduce emissions and cause the emission price to increase. A minimum price on carbon, however, would provide the best opportunity to make the ETS more robust against unforeseen events, such as a further deterioration of the economy. Such a minimum price would result in more emission reductions if abatement proves to be cheaper

  3. Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst

    Directory of Open Access Journals (Sweden)

    Istadi Istadi

    2011-11-01

    Full Text Available Major problem in CO2 reforming of methane (CORM process is coke formation which is a carbonaceous residue that can physically cover active sites of a catalyst surface and leads to catalyst deactivation. A key to develop a more coke-resistant catalyst lies in a better understanding of the methane reforming mechanism at a molecular level. Therefore, this paper is aimed to simulate a micro-kinetic approach in order to calculate coking rate in CORM reaction. Rates of encapsulating and filamentous carbon formation are also included. The simulation results show that the studied catalyst has a high activity, and the rate of carbon formation is relatively low. This micro-kinetic modeling approach can be used as a tool to better understand the catalyst deactivation phenomena in reaction via carbon deposition. Copyright © 2011 BCREC UNDIP. All rights reserved.(Received: 10th May 2011; Revised: 16th August 2011; Accepted: 27th August 2011[How to Cite: I. Istadi, D.D. Anggoro, N.A.S. Amin, and D.H.W. Ling. (2011. Catalyst Deactivation Simulation Through Carbon Deposition in Carbon Dioxide Reforming over Ni/CaO-Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering & Catalysis, 6 (2: 129-136. doi:10.9767/bcrec.6.2.1213.129-136][How to Link / DOI: http://dx.doi.org/10.9767/bcrec.6.2.1213.129-136 || or local:  http://ejournal.undip.ac.id/index.php/bcrec/article/view/1213 ] | View in  |  

  4. A carbon in molten carbonate anode model for a direct carbon fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Li Hongjiao; Liu Qinghua [Tianjin Key Laboratory of Catalysis Science and Technology, School of Chemical Engineering, Tianjin University, Weijing Road 92, Tianjin 300072 (China); State Key Laboratory for Chemical Engineering (Tianjin University), School of Chemical Engineering, Tianjin University, Weijing Road 92, Tianjin 300072 (China); Li Yongdan, E-mail: ydli@tju.edu.c [Tianjin Key Laboratory of Catalysis Science and Technology, School of Chemical Engineering, Tianjin University, Weijing Road 92, Tianjin 300072 (China); State Key Laboratory for Chemical Engineering (Tianjin University), School of Chemical Engineering, Tianjin University, Weijing Road 92, Tianjin 300072 (China)

    2010-02-15

    The electrochemical oxidation of carbon at the anode of a direct carbon fuel cell (DCFC) includes charge transfer steps and chemical steps. A microstructural model of carbon particle is built, in which perfect graphene stacks are taken as the basic building blocks of carbon. A modified mechanism taking account of the irreversibility of the process and supposing that the electrochemical oxidation of carbon takes place only at the edges of the graphene sheets is proposed. A Tafel type overall rate equation is deduced along with expressions of exchange current density (j{sub 0}) and activation polarization (eta{sub act}). The performance of carbon black and graphite as the fuel of DCFC is examined. It has been found that j{sub 0} is in the range of 0.10-6.12 mA cm{sup -2} at 923-1123 K and eta{sub act} is in the range of 0.024-0.28 V at 923-1123 K with current density in 10-120 mA cm{sup -2}. Analysis of the j{sub 0}, eta{sub act} values and the product composition reveals that the charge transfer steps as well as the oxygen ion absorption steps are both important for the reaction rate. The activity of the carbon material with respect to atom location is introduced to the open circuit potential difference (OCP) calculation with Nernst equation.

  5. Critical survey on electrode aging in molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Kinoshita, K.

    1979-12-01

    To evaluate potential electrodes for molten carbonate fuel cells, we reviewed the literature pertaining to these cells and interviewed investigators working in fuel cell technology. In this critical survey, the effect of three electrode aging processes - corrosion or oxidation, sintering, and poisoning - on these potential fuel-cell electrodes is presented. It is concluded that anodes of stabilized nickel and cathodes of lithium-doped NiO are the most promising electrode materials for molten carbonate fuel cells, but that further research and development of these electrodes are needed. In particular, the effect of contaminants such as H/sub 2/S and HCl on the nickel anode must be investigated, and methods to improve the physical strength and to increase the conductivity of NiO cathodes must be explored. Recommendations are given on areas of applied electrode research that should accelerate the commercialization of the molten carbonate fuel cell. 153 references.

  6. Technoeconomic analysis of jet fuel production from hydrolysis, decarboxylation, and reforming of camelina oil

    KAUST Repository

    Natelson, Robert H.; Wang, Weicheng; Roberts, William L.; Zering, Kelly D.

    2015-01-01

    The commercial production of jet fuel from camelina oil via hydrolysis, decarboxylation, and reforming was simulated. The refinery was modeled as being close to the farms for reduced camelina transport cost. A refinery with annual nameplate capacity of 76,000 cubic meters hydrocarbons was modeled. Assuming average camelina production conditions and oil extraction modeling from the literature, the cost of oil was 0.31$kg-1. To accommodate one harvest per year, a refinery with 1 year oil storage capacity was designed, with the total refinery costing 283 million dollars in 2014 USD. Assuming co-products are sold at predicted values, the jet fuel break-even selling price was 0.80$kg-1. The model presents baseline technoeconomic data that can be used for more comprehensive financial and risk modeling of camelina jet fuel production. Decarboxylation was compared to the commercially proven hydrotreating process. The model illustrated the importance of refinery location relative to farms and hydrogen production site.

  7. Technoeconomic analysis of jet fuel production from hydrolysis, decarboxylation, and reforming of camelina oil

    KAUST Repository

    Natelson, Robert H.

    2015-04-01

    The commercial production of jet fuel from camelina oil via hydrolysis, decarboxylation, and reforming was simulated. The refinery was modeled as being close to the farms for reduced camelina transport cost. A refinery with annual nameplate capacity of 76,000 cubic meters hydrocarbons was modeled. Assuming average camelina production conditions and oil extraction modeling from the literature, the cost of oil was 0.31$kg-1. To accommodate one harvest per year, a refinery with 1 year oil storage capacity was designed, with the total refinery costing 283 million dollars in 2014 USD. Assuming co-products are sold at predicted values, the jet fuel break-even selling price was 0.80$kg-1. The model presents baseline technoeconomic data that can be used for more comprehensive financial and risk modeling of camelina jet fuel production. Decarboxylation was compared to the commercially proven hydrotreating process. The model illustrated the importance of refinery location relative to farms and hydrogen production site.

  8. An update of ERC's carbonate fuel cell development program

    International Nuclear Information System (INIS)

    Bernard, R.; Doyon, J.; Paetsch, L.; Patel, P.; Skok, A.; Yuh, C.; Steinfeld, G.; O'Shea, T.

    1992-01-01

    ERC has made significant accomplishments in stack height scale-up, resolved issues relevant to attainment of a long useful life for the carbonate fuel cell, and progressed towards addressing organizational and financial aspects of power plant demonstration

  9. Fossil fuel subsidy reform in the WTO : Options for constraining dual pricing in the multilateral trading system

    NARCIS (Netherlands)

    Marhold, Anna

    2017-01-01

    Fossil fuel subsidies harm the environment, add to health hazards caused by air pollution, and delay the energy transition. Scholars and practitioners have therefore been exploring ways to reform and eliminate them. This paper discusses the practice of energy dual pricing in the broader context of

  10. 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......-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...... of Pd-CGO helped to mitigate sulfur deactivation effect; e.g. lowering the onset temperature (up to 190°C) for CH4 conversion during temperature-programmed reactions. Both Ni/ScYSZ and Ni/ScYSZ/Pd-CGO anode catalysts were more active for dry reforming of biogas than they were for steam reforming...

  11. 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.

  12. Performance and endurance of a high temperature PEM fuel cell operated on methanol reformate

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Grigoras, Ionela; Zhou, Fan

    2014-01-01

    This paper analyzes the effects of methanol and water vapor on the performance of a high temperature proton exchange membrane fuel cell (HT-PEMFC) at varying temperatures, ranging from 140 °C to 180 °C. For the study, a H3PO4 – doped polybenzimidazole (PBI) – based membrane electrode assembly (MEA......) of 45 cm2 active surface area from BASF was employed. The study showed overall negligible effects of methanol-water vapor mixture slips on performance, even at relatively low simulated steam methanol reforming conversion of 90%, which corresponds to 3% methanol vapor by volume in the anode gas feed....... Temperature on the other hand has significant impact on the performance of an HT-PEMFC. To assess the effects of methanol-water vapor mixture alone, CO2 and CO are not considered in these tests. The analysis is based on polarization curves and impedance spectra registered for all the test points. After...

  13. Wildland fire emissions, carbon and climate: Characterizing wildland fuels

    Science.gov (United States)

    David R. Weise; Clinton S. Wright

    2013-01-01

    Smoke from biomass fires makes up a substantial portion of global greenhouse gas, aerosol, and black carbon (GHG/A/BC) emissions. Understanding how fuel characteristics and conditions affect fire occurrence and extent, combustion dynamics, and fuel consumption is critical for making accurate, reliable estimates of emissions production at local, regional, national, and...

  14. Carbon pricing in the EU: Evaluation of different EU ETS reform options

    International Nuclear Information System (INIS)

    Brink, Corjan; Vollebergh, Herman R.J.; Werf, Edwin van der

    2016-01-01

    This paper studies various options to support allowance prices in the EU Emissions Trading System (ETS), such as adjusting the cap, an auction reserve price, and fixed and variable carbon taxes in addition to the EU ETS. We use a dynamic computable general equilibrium model that explicitly allows for allowance banking and for a detailed cost-effectiveness analysis at the EU Member State level. We find that tightening the cap provides an ad hoc solution to the fundamental issue of the robustness of the effective carbon price, while introducing a price component to the ETS brings structural carbon price support in times of negative demand shocks for emission allowances. These price-based policies still benefit from the intertemporal flexibility through the banking provision in the EU ETS by re-allocating emissions over time with stronger emission reductions in early years and emission increases in later years. A higher emission price has a larger negative impact on the new Member States' economies than on other Member States. Furthermore, introducing a carbon tax in addition to the EU ETS decreases the price of allowances, resulting in welfare gains for net buyers of allowances while net sellers are worse off. - Highlights: • We analyse reform options for European Union Emission Trading System (EU ETS) with a CGE model. • Variable carbon tax and auction reserve price support carbon price at least cost. • Price-based reforms decrease early emissions but increase later emissions through banking. • New Member States' economies are affected more than others by higher CO_2 prices. • Lower allowance prices due to a carbon tax are unfavourable to net sellers of allowances.

  15. High temperature energy storage performances of methane reforming with carbon dioxide in a tubular packed reactor

    International Nuclear Information System (INIS)

    Lu, Jianfeng; Chen, Yuan; Ding, Jing; Wang, Weilong

    2016-01-01

    Highlights: • Energy storage of methane reforming in a tubular packed reactor is investigated. • Thermochemical storage efficiency approaches maximum at optimal temperature. • Sensible heat and heat loss play important roles in the energy storage system. • The reaction and energy storage models of methane reforming reactor are established. • The simulated methane conversion and energy storage efficiency fit with experiments. - Abstract: High temperature heat transfer and energy storage performances of methane reforming with carbon dioxide in tubular packed reactor are investigated under different operating conditions. Experimental results show that the methane reforming in tubular packed reactor can efficiently store high temperature thermal energy, and the sensible heat and heat loss besides thermochemical energy storage play important role in the total energy storage process. When the operating temperature is increased, the thermochemical storage efficiency first increases for methane conversion rising and then decreases for heat loss rising. As the operating temperate is 800 °C, the methane conversion is 79.6%, and the thermochemical storage efficiency and total energy efficiency can be higher than 47% and 70%. According to the experimental system, the flow and reaction model of methane reforming is established using the laminar finite-rate model and Arrhenius expression, and the simulated methane conversion and energy storage efficiency fit with experimental data. Along the flow direction, the fluid temperature in the catalyst bed first decreases because of the endothermic reaction and then increases for the heat transfer from reactor wall. As a conclusion, the maximum thermochemical storage efficiency will be obtained under optimal operating temperature and optimal flow rate, and the total energy efficiency can be increased by the increase of bed conductivity and decrease of heat loss coefficient.

  16. Reduced Toxicity Fuel Satellite Propulsion System Including Fuel Cell Reformer with Alcohols Such as Methanol

    Science.gov (United States)

    Schneider, Steven J. (Inventor)

    2001-01-01

    A reduced toxicity fuel satellite propulsion system including a reduced toxicity propellant supply for consumption in an axial class thruster and an ACS class thruster. The system includes suitable valves and conduits for supplying the reduced toxicity propellant to the ACS decomposing element of an ACS thruster. The ACS decomposing element is operative to decompose the reduced toxicity propellant into hot propulsive gases. In addition the system includes suitable valves and conduits for supplying the reduced toxicity propellant to an axial decomposing element of the axial thruster. The axial decomposing element is operative to decompose the reduced toxicity propellant into hot gases. The system further includes suitable valves and conduits for supplying a second propellant to a combustion chamber of the axial thruster, whereby the hot gases and the second propellant auto-ignite and begin the combustion process for producing thrust.

  17. Coated powder for electrolyte matrix for carbonate fuel cell

    International Nuclear Information System (INIS)

    Iacovangelo, C.D.; Browall, K.W.

    1985-01-01

    A plurality of electrolyte carbonate-coated ceramic particle which does not differ significantly in size from that of the ceramic particle and wherein no significant portion of the ceramic particle is exposed is fabricated into a porous tape comprised of said coated-ceramic particles bonded together by the coating for use in a molten carbonate fuel cell

  18. High thermal efficiency and low emission performance of a methanol reformed gas fueled engine for hybrid electric vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Yamane, K.; Nakajima, Y.; Shudo, T.; Hiruma, M. [Musahi Inst. of Tech., Tokyo (Japan); Komatsu, H.; Takagi, Y. [Nissan Motor Co., Ltd., Yokosuka (Japan)

    2000-07-01

    An internal combustion engine (ICE) operation was carried out experimentally by using the mixture of air and fuel simulating the reformed gas as the fuel. It has been found that the engine can expectedly attain ultra-low emission and high thermal efficiency, namely 35% brake thermal efficiency in the basis of the low heat value of the theoretically reformed gas or 42% in the basis of the low heat value of methanol. By using the result for the estimation of the total thermal efficiency at the end of the motor output shaft of a hybrid electric vehicle, it has been found that the total thermal efficiency of the reformed gas engine system is 34% in case of a 120% energy increment and 33% in case of a 116% energy increment with a little higher NOx emission of 60 ppm while the counterpart of the fuel cell system is 34%. When the emission level for EZEV is required, the total thermal efficiency falls to 32% in case of a 120% energy increment and 31% in case of a 116% energy increment. From the points of the reliability proved by the long history, higher specific power and low cost, the internal combustion engine system with the thermal efficiency almost equal to that of the fuel cell (FC) system is further more practical when methanol is used as the fuel. (orig.)

  19. Cathode-supported hybrid direct carbon fuel cells

    DEFF Research Database (Denmark)

    Gil, Vanesa; Gurauskis, Jonas; Deleebeeck, Lisa

    2017-01-01

    The direct conversion of coal to heat and electricity by a hybrid direct carbon fuel cell (HDCFC) is a highly efficient and cleaner technology than the conventional combustion power plants. HDCFC is defined as a combination of solid oxide fuel cell and molten carbonate fuel cell. This work...... investigates cathode-supported cells as an alternative configuration for HDCFC, with better catalytic activity and performance. This study aims to define the best processing route to manufacture highly efficient cathode-supported cells based on La0.75Sr0.25MnO3/yttria-stabilized zirconia infiltrated backbones...

  20. Molten carbonate fuel cell integral matrix tape and bubble barrier

    International Nuclear Information System (INIS)

    Reiser, C.A.; Maricle, D.L.

    1983-01-01

    A molten carbonate fuel cell matrix material is described made up of a matrix tape portion and a bubble barrier portion. The matrix tape portion comprises particles inert to molten carbonate electrolyte, ceramic particles and a polymeric binder, the matrix tape being flexible, pliable and having rubber-like compliance at room temperature. The bubble barrier is a solid material having fine porosity preferably being bonded to the matrix tape. In operation in a fuel cell, the polymer binder burns off leaving the matrix and bubble barrier providing superior sealing, stability and performance properties to the fuel cell stack

  1. Processing of carbon composite paper as electrode for fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Mathur, R.B.; Maheshwari, Priyanka H.; Dhami, T.L. [Carbon Technology Unit, National Physical Laboratory, New Delhi 110012 (India); Sharma, R.K.; Sharma, C.P. [Soft Polymeric Group, Division of Engineering Materials, National Physical Laboratory, New Delhi 110012 (India)

    2006-10-27

    The porous carbon electrode in a fuel cell not only acts as an electrolyte and a catalyst support, but also allows the diffusion of hydrogen fuel through its fine porosity and serves as a current-carrying conductor. A suitable carbon paper electrode is developed and possesses the characteristics of high porosity, permeability and strength along with low electrical resistivity so that it can be effectively used in proton-exchange membrane and phosphoric acid fuel cells. The electrode is prepared through a combination of two important techniques, viz., paper-making technology by first forming a porous chopped carbon fibre preform, and composite technology using a thermosetting resin matrix. The study reveals an interdependence of one parameter on another and how judicious choice of the processing conditions are necessary to achieve the desired characteristics. The current-voltage performance of the electrode in a unit fuel cell matches that of a commercially-available material. (author)

  2. Less sensitive electrocatalysts towards carbon monoxide for PEMFC fed by hydrogen produced from reforming gas; Recherche de catalyseurs peu sensibles a la presence de monoxyde de carbone pour piles a combustible PEMFC alimentees en gaz de reformage

    Energy Technology Data Exchange (ETDEWEB)

    Boucher, A.C.

    2002-11-15

    The aim of this work was to prepare bimetallic catalysts based on platinum to elaborate anodes for fuel cells fed by hydrogen produced from reforming gas and containing thus some ppm of carbon monoxide. In order to avoid platinum poisoning, another metal, such as tin, was added. This leads to a more tolerant material to CO. A Pt-Sn catalyst supported on Vulcan XC-72 carbon was prepared by a chemical route, using a platinum carbonyl complex. This material was characterized by physical and chemical methods which indicate that it is formed by nano-structured Pt{sub 3}Sn particles. These particles have a narrow size distribution with a mean diameter of approximately 2 nm. Its activity towards CO, particularly under fuel cell conditions, was compared with a similar commercial E-TEK catalyst. This study shows that the catalyst prepared from the carbonyl precursor is less sensitive to CO than the commercial one. (author)

  3. Vapor Delivery Systems for the Study of the Effects of Reformate Gas Impurities in HT-PEM Fuel Cells

    DEFF Research Database (Denmark)

    Araya, Samuel Simon; Kær, Søren Knudsen; Andreasen, Søren Juhl

    2011-01-01

    , impurities in the reformate gas produced from methanol steam reforming can affect the performance and durability of fuel cells. In this paper different vapor delivery systems, intended to assist in the study of the effects of some of the impurities, are described and compared with each other. A system based...... on a pump and electrically heated evaporator was found to be more suitable for the typical flow rates involved in the anode feed of an H3PO4/PBI based HT-PEMFC unit cell assembly. Test stations composed of vapor delivery systems and mass flow controllers for testing the effects of methanol slip, water vapor...

  4. Carbon nanofiber growth on carbon paper for proton exchange membrane fuel cells

    NARCIS (Netherlands)

    Celebi, S.; Nijhuis, T.A.; Schaaf, van der J.; Bruijn, de F.A.; Schouten, J.C.

    2011-01-01

    Homogeneous deposition precipitation (HDP) of nickel has been investigated for the growth of carbon nanofibers (CNFs) on carbon paper for use in proton exchange membrane fuel cells as a gas diffusion layer. Selective CNF growth on only one side of carbon paper is required to transfer the generated

  5. California's Low-Carbon Fuel Standard - Compliance Trends

    Science.gov (United States)

    Witcover, J.; Yeh, S.

    2013-12-01

    Policies to incentivize lower carbon transport fuels have become more prevalent even as they spark heated debate over their cost and feasibility. California's approach - performance-based regulation called the Low Carbon Fuel Standard (LCFS) - has proved no exception. The LCFS aims to achieve 10% reductions in state transport fuel carbon intensity (CI) by 2020, by setting declining annual CI targets, and rewarding fuels for incremental improvements in CI beyond the targets while penalizing those that fail to meet requirements. Even as debate continues over when new, lower carbon fuels will become widely available at commercial scale, California's transport energy mix is shifting in gradual but noticeable ways under the LCFS. We analyze the changes using available data on LCFS fuels from the California Air Resources Board and other secondary sources, beginning in 2011 (the first compliance year). We examine trends in program compliance (evaluated through carbon credits and deficits generated), and relative importance of various transport energy pathways (fuel types and feedstocks, and their CI ratings, including new pathways added since the program's start). We document a roughly 2% decline in CI for gasoline and diesel substitutes under the program, with compliance achieved through small shifts toward greater reliance on fuels with lower CI ratings within a relatively stable amount of transport energy derived from alternatives to fossil fuel gasoline and diesel. We also discuss price trends in the nascent LCFS credit market. The results are important to the broader policy debate about transportation sector response to market-based policies aimed at reducing the sector's greenhouse gas emissions.

  6. An assessment of Japanese carbon tax reform using the E3MG econometric model.

    Science.gov (United States)

    Lee, Soocheol; Pollitt, Hector; Ueta, Kazuhiro

    2012-01-01

    This paper analyses the potential economic and environmental effects of carbon taxation in Japan using the E3MG model, a global macroeconometric model constructed by the University of Cambridge and Cambridge Econometrics. The paper approaches the issues by considering first the impacts of the carbon tax in Japan introduced in 2012 and then the measures necessary to reduce Japan's emissions in line with its Copenhagen pledge of -25% compared to 1990 levels. The results from the model suggest that FY2012 Tax Reform has only a small impact on emission levels and no significant impact on GDP and employment. The potential costs of reducing emissions to meet the 25% reduction target for 2020 are quite modest, but noticeable. GDP falls by around 1.2% compared to the baseline and employment by 0.4% compared to the baseline. But this could be offset, with some potential economic benefits, if revenues are recycled efficiently. This paper considers two revenue recycling scenarios. The most positive outcome is if revenues are used both to reduce income tax rates and to increase investment in energy efficiency. This paper shows there could be double dividend effects, if Carbon Tax Reform is properly designed.

  7. An Assessment of Japanese Carbon Tax Reform Using the E3MG Econometric Model

    Directory of Open Access Journals (Sweden)

    Soocheol Lee

    2012-01-01

    Full Text Available This paper analyses the potential economic and environmental effects of carbon taxation in Japan using the E3MG model, a global macroeconometric model constructed by the University of Cambridge and Cambridge Econometrics. The paper approaches the issues by considering first the impacts of the carbon tax in Japan introduced in 2012 and then the measures necessary to reduce Japan’s emissions in line with its Copenhagen pledge of −25% compared to 1990 levels. The results from the model suggest that FY2012 Tax Reform has only a small impact on emission levels and no significant impact on GDP and employment. The potential costs of reducing emissions to meet the 25% reduction target for 2020 are quite modest, but noticeable. GDP falls by around 1.2% compared to the baseline and employment by 0.4% compared to the baseline. But this could be offset, with some potential economic benefits, if revenues are recycled efficiently. This paper considers two revenue recycling scenarios. The most positive outcome is if revenues are used both to reduce income tax rates and to increase investment in energy efficiency. This paper shows there could be double dividend effects, if Carbon Tax Reform is properly designed.

  8. An Assessment of Japanese Carbon Tax Reform Using the E3MG Econometric Model

    Science.gov (United States)

    Lee, Soocheol; Pollitt, Hector; Ueta, Kazuhiro

    2012-01-01

    This paper analyses the potential economic and environmental effects of carbon taxation in Japan using the E3MG model, a global macroeconometric model constructed by the University of Cambridge and Cambridge Econometrics. The paper approaches the issues by considering first the impacts of the carbon tax in Japan introduced in 2012 and then the measures necessary to reduce Japan's emissions in line with its Copenhagen pledge of −25% compared to 1990 levels. The results from the model suggest that FY2012 Tax Reform has only a small impact on emission levels and no significant impact on GDP and employment. The potential costs of reducing emissions to meet the 25% reduction target for 2020 are quite modest, but noticeable. GDP falls by around 1.2% compared to the baseline and employment by 0.4% compared to the baseline. But this could be offset, with some potential economic benefits, if revenues are recycled efficiently. This paper considers two revenue recycling scenarios. The most positive outcome is if revenues are used both to reduce income tax rates and to increase investment in energy efficiency. This paper shows there could be double dividend effects, if Carbon Tax Reform is properly designed. PMID:23365531

  9. Coupling of a 2.5 kW steam reformer with a 1 kW el PEM fuel cell

    Science.gov (United States)

    Mathiak, J.; Heinzel, A.; Roes, J.; Kalk, Th.; Kraus, H.; Brandt, H.

    The University of Duisburg-Essen has developed a compact multi-fuel steam reformer suitable for natural gas, propane and butane. This steam reformer was combined with a polymer electrolyte membrane fuel cell (PEM FC) and a system test of the process chain was performed. The fuel processor comprises a prereformer step, a primary reformer, water gas shift reactors, a steam generator, internal heat exchangers in order to achieve an optimised heat integration and an external burner for heat supply as well as a preferential oxidation step (PROX) as CO purification. The fuel processor is designed to deliver a thermal hydrogen power output from 500 W to 2.5 kW. The PEM fuel cell stack provides about 1 kW electrical power. In the following paper experimental results of measurements of the single components PEM fuel cell and fuel processor as well as results of the coupling of both to form a process chain are presented.

  10. Performance evaluation and comparison of fuel processors integrated with PEM fuel cell based on steam or autothermal reforming and on CO preferential oxidation or selective methanation

    International Nuclear Information System (INIS)

    Ercolino, Giuliana; Ashraf, Muhammad A.; Specchia, Vito; Specchia, Stefania

    2015-01-01

    Highlights: • Modeling of different fuel processors integrated with PEM fuel cell stack. • Steam or autothermal reforming + CO selective methanation or preferential oxidation. • Reforming of different hydrocarbons: gasoline, light diesel oil, natural gas. • 5 kW e net systems comparison via energy efficiency and primary fuel rate consumed. • Highest net efficiency: steam reformer + CO selective methanation based system. - Abstract: The performances of four different auxiliary power unit (APU) schemes, based on a 5 kW e net proton exchange membrane fuel cell (PEM-FC) stack, are evaluated and compared. The fuel processor section of each APU is characterized by a reformer (autothermal ATR or steam SR), a non-isothermal water gas shift (NI-WGS) reactor and a final syngas catalytic clean-up step: the CO preferential oxidation (PROX) reactor or the CO selective methanation (SMET) one. Furthermore, three hydrocarbon fuels, the most commonly found in service stations (gasoline, light diesel oil and natural gas) are considered as primary fuels. The comparison is carried out examining the results obtained by a series of steady-state system simulations in Aspen Plus® of the four different APU schemes by varying the fed fuel. From the calculated data, the performance of CO-PROX is not very different compared to that of the CO-SMET, but the performance of the SR based APUs is higher than the scheme of the ATR based APUs. The most promising APU scheme with respect to an overall performance target is the scheme fed with natural gas and characterized by a fuel processor chain consisting of SR, NI-WGS and CO-SMET reactors. This processing reactors scheme together with the fuel cell section, notwithstanding having practically the same energy efficiency of the scheme with SR, NI-WGS and CO-PROX reactors, ensures a less complex scheme, higher hydrogen concentration in the syngas, lower air mass rate consumption, the absence of nitrogen in the syngas and higher potential

  11. Tendances Carbone no. 73 'Reforming the EU ETS, Act I: pushing back the allowance auction timetable'

    International Nuclear Information System (INIS)

    Alberola, Emilie

    2012-01-01

    Among the publications of CDC Climat Research, 'Tendances Carbone' bulletin specifically studies the developments of the European market for CO 2 allowances. This issue addresses the following points: On July 25 2012, the European Commission presented its first reform to re-calibrate the supply of allowances in EU ETS, via two proposals aimed at amending the ETS Directive and reviewing the auction regulations, in order to alter the auctioning timetable during the period between 2013 and 2020, with no legal risk. The aim is to withdraw a certain amount of the allowances auctioned in 2013, 2014 and 2015, in order to reintroduce that amount after 2018

  12. Thermal and chemical analysis of carbon dioxide reforming of methane using the out-of-pile test facility

    International Nuclear Information System (INIS)

    Huang Ziyong; Ohashi, Hirofumi; Inagaki, Yoshiyuki

    2000-03-01

    In the Japan Atomic Energy Research Institute, a hydrogen production system is being designed to produce hydrogen by means of steam reforming of natural gas (its main composition is methane(CH 4 )) using nuclear heat (10 MW, 1178 K) supplied by the High Temperature Engineering Test Reactor (HTTR). Prior to coupling of the steam reforming system with the HTTR, an out-of-pile demonstration test was planned to confirm safety, controllability and performance of the steam reforming system under simulated operational conditions of the prototype. The out-of-pile test facility simulates key components downstream to an intermediate heat exchanger of the HTTR hydrogen production system on a scale of 1 : 30 and has a hydrogen production capacity of 110 Nm 3 /h using an electric heater as a reactor substitute. The test facility is presently under construction. Reforming of natural gas with carbon dioxide CO 2 (CO 2 reforming) using the out-of-pile test facility is also being considered. In recent years, catalytic reforming of natural gas with CO 2 to synthesis gas (CO and H 2 ) has been proposed as one of the most promising technologies for utilization of those two greenhouse gases. Numerical analysis on heat and mass balance has practical significance in CO 2 reforming when the steam reforming process is adopted in the out-of-pile test. Numerical analysis of CO 2 reforming and reforming of natural gas with CO 2 and steam (CO 2 +H 2 O reforming) have been carried out using the mathematical model. Results such as the methane conversion rate, product gas composition, and the components temperature distribution considering the effects of helium gas temperature, reforming pressure, molar ratio of process gases and so on have been obtained in the numerical analysis. Heat and mass balance of the out-of-pile test facility considering chemical reactions are evaluated well. The methane conversation rates are about 0.36 and 0.35 which correspond to the equilibrium at 1085 and 1100 K for

  13. Thermal and chemical analysis of carbon dioxide reforming of methane using the out-of-pile test facility

    Energy Technology Data Exchange (ETDEWEB)

    Huang Ziyong [Institute of Nuclear Energy Technology, Tsinghua University (China); Ohashi, Hirofumi; Inagaki, Yoshiyuki [Department of Advanced Nuclear Heat Technology, Oarai Research Establishment, Japan Atomic Energy Research Institute, Oarai, Ibaraki (Japan)

    2000-03-01

    In the Japan Atomic Energy Research Institute, a hydrogen production system is being designed to produce hydrogen by means of steam reforming of natural gas (its main composition is methane(CH{sub 4})) using nuclear heat (10 MW, 1178 K) supplied by the High Temperature Engineering Test Reactor (HTTR). Prior to coupling of the steam reforming system with the HTTR, an out-of-pile demonstration test was planned to confirm safety, controllability and performance of the steam reforming system under simulated operational conditions of the prototype. The out-of-pile test facility simulates key components downstream to an intermediate heat exchanger of the HTTR hydrogen production system on a scale of 1 : 30 and has a hydrogen production capacity of 110 Nm{sup 3}/h using an electric heater as a reactor substitute. The test facility is presently under construction. Reforming of natural gas with carbon dioxide CO{sub 2} (CO{sub 2} reforming) using the out-of-pile test facility is also being considered. In recent years, catalytic reforming of natural gas with CO{sub 2} to synthesis gas (CO and H{sub 2}) has been proposed as one of the most promising technologies for utilization of those two greenhouse gases. Numerical analysis on heat and mass balance has practical significance in CO{sub 2} reforming when the steam reforming process is adopted in the out-of-pile test. Numerical analysis of CO{sub 2} reforming and reforming of natural gas with CO{sub 2} and steam (CO{sub 2}+H{sub 2}O reforming) have been carried out using the mathematical model. Results such as the methane conversion rate, product gas composition, and the components temperature distribution considering the effects of helium gas temperature, reforming pressure, molar ratio of process gases and so on have been obtained in the numerical analysis. Heat and mass balance of the out-of-pile test facility considering chemical reactions are evaluated well. The methane conversation rates are about 0.36 and 0.35 which

  14. Results of industrial tests of carbonate additive to fuel oil

    Science.gov (United States)

    Zvereva, E. R.; Dmitriev, A. V.; Shageev, M. F.; Akhmetvalieva, G. R.

    2017-08-01

    Fuel oil plays an important role in the energy balance of our country. The quality of fuel oil significantly affects the conditions of its transport, storage, and combustion; release of contaminants to atmosphere; and the operation of main and auxiliary facilities of HPPs. According to the Energy Strategy of Russia for the Period until 2030, the oil-refining ratio gradually increases; as a result, the fraction of straight-run fuel oil in heavy fuel oils consistently decreases, which leads to the worsening of performance characteristics of fuel oil. Consequently, the problem of the increase in the quality of residual fuel oil is quite topical. In this paper, it is suggested to treat fuel oil by additives during its combustion, which would provide the improvement of ecological and economic indicators of oil-fired HPPs. Advantages of this method include simplicity of implementation, low energy and capital expenses, and the possibility to use production waste as additives. In the paper, the results are presented of industrial tests of the combustion of fuel oil with the additive of dewatered carbonate sludge, which is formed during coagulation and lime treatment of environmental waters on HPPs. The design of a volume delivery device is developed for the steady additive input to the boiler air duct. The values are given for the main parameters of the condition of a TGM-84B boiler plant. The mechanism of action of dewatered carbonate sludge on sulfur oxides, which are formed during fuel oil combustion, is considered. Results of industrial tests indicate the decrease in the mass fraction of discharged sulfur oxides by 36.5%. Evaluation of the prevented damage from sulfur oxide discharged into atmospheric air shows that the combustion of the fuel oil of 100 brand using carbonate sludge as an additive (0.1 wt %) saves nearly 6 million rubles a year during environmental actions at the consumption of fuel oil of 138240 t/year.

  15. Dynamic Modeling of a Reformed Methanol Fuel Cell System using Empirical Data and Adaptive Neuro-Fuzzy Inference System Models

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Shaker, Hamid Reza

    2013-01-01

    In this work, a dynamic MATLAB Simulink model of a H3-350 Reformed Methanol Fuel Cell (RMFC) stand-alone battery charger produced by Serenergy is developed on the basis of theoretical and empirical methods. The advantage of RMFC systems is that they use liquid methanol as a fuel instead of gaseous...... of the reforming process are implemented. Models of the cooling flow of the blowers for the fuel cell and the burner which supplies process heat for the reformer are made. The two blowers have a common exhaust, which means that the two blowers influence each other’s output. The models take this into account using...... an empirical approach. Fin efficiency models for the cooling effect of the air are also developed using empirical methods. A fuel cell model is also implemented based on a standard model which is adapted to fit the measured performance of the H3-350 module. All the individual parts of the model are verified...

  16. Dynamic Modeling of a Reformed Methanol Fuel Cell System using Empirical Data and Adaptive Neuro-Fuzzy Inference System Models

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær; Andreasen, Søren Juhl; Shaker, Hamid Reza

    2014-01-01

    In this work, a dynamic MATLAB Simulink model of a H3-350 Reformed Methanol Fuel Cell (RMFC) stand-alone battery charger produced by Serenergy is developed on the basis of theoretical and empirical methods. The advantage of RMFC systems is that they use liquid methanol as a fuel instead of gaseous...... of the reforming process are implemented. Models of the cooling flow of the blowers for the fuel cell and the burner which supplies process heat for the reformer are made. The two blowers have a common exhaust, which means that the two blowers influence each other’s output. The models take this into account using...... an empirical approach. Fin efficiency models for the cooling effect of the air are also developed using empirical methods. A fuel cell model is also implemented based on a standard model which is adapted to fit the measured performance of the H3-350 module. All the individual parts of the model are verified...

  17. Carbon dioxide from fossil fuels: adapting to uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Chen, K; Winter, R C; Bergman, M K

    1980-12-01

    If present scientific information is reasonable, the world is likely to experience noticeable global warming by the beginning of the next century if high annual growth rates of fossil-fuel energy use continue. Only with optimistic assumptions and low growth rates will carbon-dioxide-induced temperature increases be held below 2/sup 0/C or so over the next century. Conservation, flexible energy choices, and control options could lessen the potential effects of carbon dioxide. Though perhaps impractical from the standpoint of costs and efficiency losses, large coastal centralized facilities would be the most amenable to carbon dioxide control and disposal. Yet no country can control carbon dioxide levels unilaterally. The USA, however, which currently contributes over a quarter of all fossil-fuel carbon dioxide emissions and possesses a quarter of the world's coal resources, could provide a much needed role in leadership, research and education. 70 references.

  18. Dynamic simulation of a direct carbonate fuel cell power plant

    Energy Technology Data Exchange (ETDEWEB)

    Ernest, J.B. [Fluor Daniel, Inc., Irvine, CA (United States); Ghezel-Ayagh, H.; Kush, A.K. [Fuel Cell Engineering, Danbury, CT (United States)

    1996-12-31

    Fuel Cell Engineering Corporation (FCE) is commercializing a 2.85 MW Direct carbonate Fuel Cell (DFC) power plant. The commercialization sequence has already progressed through construction and operation of the first commercial-scale DFC power plant on a U.S. electric utility, the 2 MW Santa Clara Demonstration Project (SCDP), and the completion of the early phases of a Commercial Plant design. A 400 kW fuel cell stack Test Facility is being built at Energy Research Corporation (ERC), FCE`s parent company, which will be capable of testing commercial-sized fuel cell stacks in an integrated plant configuration. Fluor Daniel, Inc. provided engineering, procurement, and construction services for SCDP and has jointly developed the Commercial Plant design with FCE, focusing on the balance-of-plant (BOP) equipment outside of the fuel cell modules. This paper provides a brief orientation to the dynamic simulation of a fuel cell power plant and the benefits offered.

  19. Methane steam reforming kinetics over Ni-YSZ anodematerials for Solid Oxide FuelCells

    DEFF Research Database (Denmark)

    Mogensen, David

    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...

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

    DEFF Research Database (Denmark)

    Mogensen, David

    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...

  1. CAPTURING EXHAUST CO2 GAS USING MOLTEN CARBONATE FUEL CELLS

    Directory of Open Access Journals (Sweden)

    Prateek Dhawan

    2016-03-01

    Full Text Available Carbon dioxide is considered as one of the major contenders when the question of greenhouse effect arises. So for any industry or power plant it is of utmost importance to follow certain increasingly stringent environment protection rules and laws. So it is significant to keep eye on any possible methods to reduce carbon dioxide emissions in an efficient way. This paper reviews the available literature so as to try to provide an insight of the possibility of using Molten Carbonate Fuel Cells (MCFCs as the carbon capturing and segregating devices and the various factors that affect the performance of MCFCs during the process of CO2 capture.

  2. Interactions between California's Low Carbon Fuel Standard and the National Renewable Fuel Standard

    International Nuclear Information System (INIS)

    Whistance, Jarrett; Thompson, Wyatt; Meyer, Seth

    2017-01-01

    This study investigates the economic interactions between a national renewable fuel policy, namely the Renewable Fuel Standard (RFS) in the United States, and a sub-national renewable fuel policy, the Low Carbon Fuel Standard (LCFS) in California. The two policies have a similar objective of reducing greenhouse gas emissions, but the policies differ in the manner in which those objectives are met. The RFS imposes a hierarchical mandate of renewable fuel use for each year whereas the LCFS imposes a specific annual carbon-intensity reduction with less of a fuel specific mandate. We model the interactions using a partial-equilibrium structural model of agricultural and energy markets in the US and Rest-of-World regions. Our results suggest the policies are mutually reinforcing in that the compliance costs of meeting one of the requirements is lower in the presence of the other policy. In addition, the two policies combine to create a spatial shift in renewable fuel use toward California even though overall renewable fuel use remains relatively unchanged. - Highlights: • Results suggest the RFS and LCFS are mutually reinforcing. • Overall level of renewable fuel use is similar across scenarios. • Renewable fuel use shifts toward California in the presence of the LCFS. • Higher ethanol blend (e.g. E85) use also shifts toward California.

  3. Feasability of the direct generation of hydrogen for fuel-cell-powered vehicles by on-board steam reforming of naphta

    NARCIS (Netherlands)

    Darwish, Naif A.; Hilal, Nidal; Versteeg, Geert; Heesink, Albertus B.M.

    2004-01-01

    A process flow sheet for the production of hydrogen to run a 50 kW fuel-cell-powered-vehicle by steam reforming of naphtha is presented. The major units in the flow sheet involve a desulfurization unit, a steam reformer, a low temperature (LT) shift reactor, a methanation reactor, and a membrane

  4. Feasibility of the direct generation of hydrogen for fuel-cell-powered vehicles by on-board steam reforming of naphtha

    NARCIS (Netherlands)

    Darwish, Naif A.; Hilal, Nidal; Versteeg, Geert; Heesink, Bert

    2004-01-01

    A process flow sheet for the production of hydrogen to run a 50 kW fuel-cell-powered-vehicle by steam reforming of naphtha is presented. The major units in the flow sheet involve a desulfurization unit, a steam reformer, a low temperature (LT) shift reactor, a methanation reactor, and a membrane

  5. Method for generating hydrogen for fuel cells

    Science.gov (United States)

    Ahmed, Shabbir; Lee, Sheldon H. D.; Carter, John David; Krumpelt, Michael

    2004-03-30

    A method of producing a H.sub.2 rich gas stream includes supplying an O.sub.2 rich gas, steam, and fuel to an inner reforming zone of a fuel processor that includes a partial oxidation catalyst and a steam reforming catalyst or a combined partial oxidation and stream reforming catalyst. The method also includes contacting the O.sub.2 rich gas, steam, and fuel with the partial oxidation catalyst and the steam reforming catalyst or the combined partial oxidation and stream reforming catalyst in the inner reforming zone to generate a hot reformate stream. The method still further includes cooling the hot reformate stream in a cooling zone to produce a cooled reformate stream. Additionally, the method includes removing sulfur-containing compounds from the cooled reformate stream by contacting the cooled reformate stream with a sulfur removal agent. The method still further includes contacting the cooled reformate stream with a catalyst that converts water and carbon monoxide to carbon dioxide and H.sub.2 in a water-gas-shift zone to produce a final reformate stream in the fuel processor.

  6. Electrochemical Impedance Spectroscopy (EIS) Characterization of Reformate-operated High Temperature PEM Fuel Cell Stack

    DEFF Research Database (Denmark)

    Sahlin, Simon Lennart; Simon Araya, Samuel; Andreasen, Søren Juhl

    2017-01-01

    their effects on a reformate-operated stack. Polarization curves were also recorded to complement the impedance analysis of the researched phenomena. An equivalent circuit model was used to estimate the different resistances at varying parameters. It showed a significantly higher low frequency resistance......, λanode= 1.6 for reformate operation and λcathode= 4.The work also compared dry hydrogen, steam reforming and autothermal reforming gas feeds at160 ◦Cand showed appreciably lower performance in the case of autothermal reforming at the same stoichiometry, mainly attributable to mass transport related...

  7. 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)

  8. Dry reforming of coke oven gases over activated carbon to produce syngas for methanol synthesis

    Energy Technology Data Exchange (ETDEWEB)

    J.M. Bermudez; B. Fidalgo; A. Arenillas; J.A. Menendez [Instituto Nacional del Carbn, Oviedo (Spain)

    2010-10-15

    The dry reforming of coke oven gases (COG) over an activated carbon used as catalyst has been studied in order to produce a syngas suitable for methanol synthesis. The primary aim of this work was to study the influence of the high amount of hydrogen present in the COG on the process of dry reforming, as well as the influence of other operation conditions, such us temperature and volumetric hourly space velocity (VHSV). It was found that the reverse water gas shift (RWGS) reaction takes place due to the hydrogen present in the COG, and that its influence on the process increases as the temperature decreases. This situation may give rise to the consumption of the hydrogen present in the COG, and the consequent formation of a syngas which is inappropriate for the synthesis of methanol. This reaction can be avoided by working at high temperatures (about 1000{sup o}C) in order to produce a syngas that is suitable for methanol synthesis. It was also found that the RWGS reaction is favoured by an increase in the VHSV. In addition, the active carbon FY5 was proven to be an adequate catalyst for the production of syngas from COG. 25 refs., 7 figs., 2 tabs.

  9. Template-Assisted Wet-Combustion Synthesis of Fibrous Nickel-Based Catalyst for Carbon Dioxide Methanation and Methane Steam Reforming.

    Science.gov (United States)

    Aghayan, M; Potemkin, D I; Rubio-Marcos, F; Uskov, S I; Snytnikov, P V; Hussainova, I

    2017-12-20

    Efficient capture and recycling of CO 2 enable not only prevention of global warming but also the supply of useful low-carbon fuels. The catalytic conversion of CO 2 into an organic compound is a promising recycling approach which opens new concepts and opportunities for catalytic and industrial development. Here we report about template-assisted wet-combustion synthesis of a one-dimensional nickel-based catalyst for carbon dioxide methanation and methane steam reforming. Because of a high temperature achieved in a short time during reaction and a large amount of evolved gases, the wet-combustion synthesis yields homogeneously precipitated nanoparticles of NiO with average particle size of 4 nm on alumina nanofibers covered with a NiAl 2 O 4 nanolayer. The as-synthesized core-shell structured fibers exhibit outstanding activity in steam reforming of methane and sufficient activity in carbon dioxide methanation with 100% selectivity toward methane formation. The as-synthesized catalyst shows stable operation under the reaction conditions for at least 50 h.

  10. Production of Solar Fuels by Photoelectrochemical Conversion of Carbon Dioxide

    OpenAIRE

    Irtem, Ibrahim Erdem

    2017-01-01

    Growing global emission of carbon dioxide gas (CO2) reflects the world’s energy dependence on fossil fuels. The conversion of CO2 emission into value-added products, like fuels completes a circular CO2 economy which requires a renewable energy conversion and storage system. Amongst a few, photo/electrochemistry has been particularly appealing thanks to its energy efficiency and enormous potential for industrial applications. Formic acid (HCOOH) production from CO2 reduction appears as an al...

  11. Coating applications for the molten carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A.; Skok, A.J.; Patel, P.S.; Maru, H.C.

    1981-09-25

    The molten carbonate fuel cell is a highly efficient low polluting fuel-to-electricity conversion device which is at present being developed for power plant and industrial use. Because the alkali carbonates at the operating temperature of 650/sup 0/C are corrosive and the methods employed for sealing the cell lead to certain electrochemical corrosion couples, different types of protective coatings are needed to minimize attack in a cost-effective manner. Besides protective purposes, other opportunities are also described where coating technology can be gainfully employed in this system.

  12. The Role of Synthetic Fuels for a Carbon Neutral Economy

    Directory of Open Access Journals (Sweden)

    Rui Namorado Rosa

    2017-04-01

    Full Text Available Fossil fuels depletion and increasing environmental impacts arising from their use call for seeking growing supplies from renewable and nuclear primary energy sources. However, it is necessary to simultaneously attend to both the electrical power needs and the specificities of the transport and industrial sector requirements. A major question posed by the shift away from traditional fossil fuels towards renewable energy sources lies in matching the power demand with the daily and seasonal oscillation and the intermittency of these natural energy fluxes. Huge energy storage requirements become necessary or otherwise the decline of the power factor of both the renewable and conventional generation would mean loss of resources. On the other hand, liquid and gaseous fuels, for which there is vast storage and distribution capacity available, appear essential to supply the transport sector for a very long time ahead, besides their domestic and industrial roles. Within this context, the present assessment suggests that proven technologies and sound tested principles are available to develop an integrated energy system, relying on synthetic fuels. These would incorporate carbon capture and utilization in a closed carbon cycle, progressively relying mostly on solar and/or nuclear primary sources, providing both electric power and gaseous/liquid hydrocarbon fuels, having ample storage capacity, and able to timely satisfy all forms of energy demand. The principles and means are already available to develop a carbon-neutral synthetic fuel economy.

  13. Control and experimental characterization of a methanol reformer for a 350W high temperature polymer electrolyte membrane fuel cell system

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Kær, Søren Knudsen; Jensen, Hans-Christian Becker

    suited for reformer systems, where high CO tolerance is required. This enables the use fuels based on e.g. liquid alcohols. This work presents the control strategies of a methanol refoermer for a 350W HTPEM FC system. The system examined is the Serenergy H3-350 Mobile Battery Charger, an integrated......High temperature polymer electrolyte membrane(HTPEM) fuel cells offer many advantages due to their increased operating tempera-tures compared to similar Nafion-based membrane tech-nologies, that rely on the conductive abilities of liquid water. The polybenzimidazole (PBI) membranes are especially...

  14. Liquid and Gaseous Fuel from Waste Plastics by Sequential Pyrolysis and Catalytic Reforming Processes over Indonesian Natural Zeolite Catalysts

    Directory of Open Access Journals (Sweden)

    Mochamad Syamsiro

    2014-08-01

    Full Text Available In this study, the performance of several differently treated natural zeolites in a sequential pyrolysis and catalytic reforming of plastic materials i.e. polypropylene (PP and polystyrene (PS were investigated. The experiments were carried out on two stage reactor using semi-batch system. The samples were degraded at 500°C in the pyrolysis reactor and then reformed at 450°C in the catalytic reformer. The results show that the mordenite-type natural zeolites could be used as efficient catalysts for the conversion of PP and PS into liquid and gaseous fuel. The treatment of natural zeolites in HCl solution showed an increase of the surface area and the Si/Al ratio while nickel impregnation increased the activity of catalyst. As a result, liquid product was reduced while gaseous product was increased. For PP, the fraction of gasoline (C5-C12 increased in the presence of catalysts. Natural zeolite catalysts could also be used to decrease the heavy oil fraction (>C20. The gaseous products were found that propene was dominated in all conditions. For PS, propane and propene were the main components of gases in the presence of nickel impregnated natural zeolite catalyst. Propene was dominated in pyrolysis over natural zeolite catalyst. The high quality of gaseous product can be used as a fuel either for driving gas engines or for dual-fuel diesel engine.

  15. Distributional effects of a carbon tax in broader U.S. fiscal reform

    International Nuclear Information System (INIS)

    Mathur, Aparna; Morris, Adele C.

    2014-01-01

    This paper analyzes the distributional implications of an illustrative $15 carbon tax imposed in 2010 on carbon in fossil fuels. We analyze its incidence across income classes and regions, both in isolation and when combined with measures that apply the carbon tax revenue to lowering other distortionary taxes in the economy. Consistent with earlier findings, we find that a carbon tax is regressive. Using tax swap simulations, we then subtract the burden of other taxes the carbon tax revenue could displace, and compute the net effect on households under three assumptions about how capital and labor income might be distributed. - Highlights: • Shows that a carbon tax by itself is regressive. • Burden of a carbon tax may be offset partly with a corporate tax swap. • Higher income households face negative tax rates under corporate tax swap. • Corporate tax swap results in wider regional variations in burden than labor tax swaps. • Adding sources side incidence of carbon tax makes tax less regressive

  16. Carbonate fuel cell and components thereof for in-situ delayed addition of carbonate electrolyte

    Science.gov (United States)

    Johnsen, Richard [Waterbury, CT; Yuh, Chao-Yi [New Milford, CT; Farooque, Mohammad [Danbury, CT

    2011-05-10

    An apparatus and method in which a delayed carbonate electrolyte is stored in the storage areas of a non-electrolyte matrix fuel cell component and is of a preselected content so as to obtain a delayed time release of the electrolyte in the storage areas in the operating temperature range of the fuel cell.

  17. Monthly, global emissions of carbon dioxide from fossil fuel consumption

    DEFF Research Database (Denmark)

    Andres, R.J.; Gregg, Jay Sterling; Losey, L.

    2011-01-01

    This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950–2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80......% of global total emissions. These data were then used in a Monte Carlo approach to proxy for all remaining countries. The proportional-proxy methodology estimates by fuel group the fraction of annual emissions emitted in each country and month. Emissions from solid, liquid and gas fuels are explicitly...

  18. All ceramic structure for molten carbonate fuel cell

    Science.gov (United States)

    Smith, James L.; Kucera, Eugenia H.

    1992-01-01

    An all-ceramic molten carbonate fuel cell having a composition formed of a multivalent metal oxide or oxygenate such as an alkali metal, transition metal oxygenate. The structure includes an anode and cathode separated by an electronically conductive interconnect. The electrodes and interconnect are compositions ceramic materials. Various combinations of ceramic compositions for the anode, cathode and interconnect are disclosed. The fuel cell exhibits stability in the fuel gas and oxidizing environments. It presents reduced sealing and expansion problems in fabrication and has improved long-term corrosion resistance.

  19. FEEDSTOCK-FLEXIBLE REFORMER SYSTEM (FFRS) FOR SOLID OXIDE FUEL CELL (SOFC)- QUALITY SYNGAS

    Energy Technology Data Exchange (ETDEWEB)

    Jezierski, Kelly; Tadd, Andrew; Schwank, Johannes; Kibler, Roland; McLean, David; Samineni, Mahesh; Smith, Ryan; Parvathikar, Sameer; Mayne, Joe; Westrich, Tom; Mader, Jerry; Faubert, F. Michael

    2010-07-30

    The U.S. Department of Energy National Energy Technology Laboratory funded this research collaboration effort between NextEnergy and the University of Michigan, who successfully designed, built, and tested a reformer system, which produced highquality syngas for use in SOFC and other applications, and a novel reactor system, which allowed for facile illumination of photocatalysts. Carbon and raw biomass gasification, sulfur tolerance of non-Platinum Group Metals (PGM) based (Ni/CeZrO2) reforming catalysts, photocatalysis reactions based on TiO2, and mild pyrolysis of biomass in ionic liquids (ILs) were investigated at low and medium temperatures (primarily 450 to 850 C) in an attempt to retain some structural value of the starting biomass. Despite a wide range of processes and feedstock composition, a literature survey showed that, gasifier products had narrow variation in composition, a restriction used to develop operating schemes for syngas cleanup. Three distinct reaction conditions were investigated: equilibrium, autothermal reforming of hydrocarbons, and the addition of O2 and steam to match the final (C/H/O) composition. Initial results showed rapid and significant deactivation of Ni/CeZrO2 catalysts upon introduction of thiophene, but both stable and unstable performance in the presence of sulfur were obtained. The key linkage appeared to be the hydrodesulfurization activity of the Ni reforming catalysts. For feed stoichiometries where high H2 production was thermodynamically favored, stable, albeit lower, H2 and CO production were obtained; but lower thermodynamic H2 concentrations resulted in continued catalyst deactivation and eventual poisoning. High H2 levels resulted in thiophene converting to H2S and S surface desorption, leading to stable performance; low H2 levels resulted in unconverted S and loss in H2 and CO production, as well as loss in thiophene conversion. Bimetallic catalysts did not outperform Ni-only catalysts, and small Ni particles were

  20. Carbon Risk and the Fossil Fuel Industry

    International Nuclear Information System (INIS)

    Mathieu, Carole

    2015-04-01

    As calls for ambitious climate action intensify, questions arise concerning the resilience of the fossil fuel industry in a world ever more inclined to favour climate protection. This article will attempt to assess the extent of present risks and show how the strength of debate can affect practices and strategy employed by companies in this sector. (author)

  1. Fuel carbon intensity standards may not mitigate climate change

    International Nuclear Information System (INIS)

    Plevin, Richard J.; Delucchi, Mark A.; O’Hare, Michael

    2017-01-01

    To mitigate the climate change effects of transportation, the US states of California and Oregon, the Canadian province of British Columbia, and the European Union have implemented regulations to reduce the life cycle greenhouse gas (GHG) emissions intensity of transport fuel, commonly referred to as 'carbon intensity', or CI. In this article, we unpack the theory and practice of fuel CI standards, examining claims regarding climate-change mitigation. We show that these standards do not reliably mitigate climate change because estimates of GHG reductions rely primarily on models that are not designed to estimate changes in emissions and climate impacts. Some regulations incorporate models that estimate a subset of changes in emissions, but the models must project changes in global markets over decades, and there is little agreement about the best model structure or parameter values. Since multiple models and projections may be equally plausible, fuel CI is inevitably subjective and unverifiable. We conclude that regulating or taxing observable emissions would more reliably achieve emission reduction. - Highlights: • Use of fuel carbon intensity (CI) standards has been expanding recently. • Fuel CI ratings are subjective, scenario- and model-dependent. • Uncertainty in fuel CI ratings creates uncertainty in policy outcomes. • There is no reliable test of whether fuel CI standards mitigate climate change. • Regulating or taxing observable emissions would be a more reliable approach.

  2. Synthesis of carbon-supported nickel catalysts for the dry reforming of CH{sub 4}

    Energy Technology Data Exchange (ETDEWEB)

    Fidalgo, B.; Zubizarreta, L.; Bermudez, J.M.; Arenillas, A.; Menendez, J.A. [Instituto Nacional del Carbon, CSIC, Apartado 73, 33080 Oviedo (Spain)

    2010-07-15

    A series of carbon-based nickel (Ni) catalysts was prepared in order to investigate the effect of the preparation method on the dispersion of Ni and its final catalytic activity in the dry reforming of methane, i.e. CH{sub 4} + CO{sub 2} 2H{sub 2} + 2CO. Three parameters were studied: (i) the influence of the surface chemistry of the carbon used as support; (ii) the method of drying (conventional vs. microwave drying); and, (iii) the temperature of the reduction stage. In order to study the role of the surface chemistry of the commercial activated carbon used as support, the active carbon was tested as received and oxidized. Although a better Ni dispersion was achieved over the oxidized support, the conversions were much lower. It was also found that microwave drying offers various advantages over conventional drying, the main one being that less time is required to prepare the catalyst. Two reduction temperatures were used (300 and 500 C), being found that it is necessary to adjust this parameter to prevent the Ni particles from sintering. (author)

  3. Cumulative emissions, unburnable fossil fuel, and the optimal carbon tax

    NARCIS (Netherlands)

    van der Ploeg, F.; Rezai, A.

    2017-01-01

    A stylised analytical framework is used to show how the global carbon tax and the amount of untapped fossil fuel can be calculated from a simple rule given estimates of society's rate of time impatience and intergenerational inequality aversion, the extraction cost technology, the rate of technical

  4. ATTACK ON WATER BY CARBON OF SOLID FUEL

    Directory of Open Access Journals (Sweden)

    N. S. Nazarov

    2008-01-01

    Full Text Available The paper considers a continuous method for attack of high temperature water steam by carbon of solid fuel (coke. Design of water-coal gas generator and experimental stand, methodology for  measurements of parameters of water-coal gasification are described in the paper.

  5. Research and development issues for molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Krumpelt, M.

    1996-04-01

    This paper describes issues pertaining to the development of molten carbonate fuel cells. In particular, the corrosion resistance and service life of nickel oxide cathodes is described. The resistivity of lithium oxide/iron oxides and improvement with doping is addressed.

  6. The nuclear fuel cycle versus the carbon cycle

    International Nuclear Information System (INIS)

    Ewing, R.C.

    2005-01-01

    Nuclear power provides approximately 17% of the world's electricity, which is equivalent to a reduction in carbon emissions of ∼0.5 gigatonnes (Gt) of C/yr. This is a modest reduction as compared with global emissions of carbon, ∼7 Gt C/yr. Most analyses suggest that in order to have a significant and timely impact on carbon emissions, carbon-free sources, such as nuclear power, would have to expand total production of energy by factors of three to ten by 2050. A three-fold increase in nuclear power capacity would result in a projected reduction in carbon emissions of 1 to 2 Gt C/yr, depending on the type of carbon-based energy source that is displaced. This three-fold increase utilizing present nuclear technologies would result in 25,000 metric tonnes (t) of spent nuclear fuel (SNF) per year, containing over 200 t of plutonium. This is compared to a present global inventory of approximately 280,000 t of SNF and >1,700 t of Pu. A nuclear weapon can be fashioned from as little as 5 kg of 239 Pu. However, there is considerable technological flexibility in the nuclear fuel cycle. There are three types of nuclear fuel cycles that might be utilized for the increased production of energy: open, closed, or a symbiotic combination of different types of reactor (such as, thermal and fast neutron reactors). The neutron energy spectrum has a significant effect on the fission product yield, and the consumption of long-lived actinides, by fission, is best achieved by fast neutrons. Within each cycle, the volume and composition of the high-level nuclear waste and fissile material depend on the type of nuclear fuel, the amount of burn-up, the extent of radionuclide separation during reprocessing, and the types of materials used to immobilize different radionuclides. As an example, a 232 Th-based fuel cycle can be used to breed fissile 233 U with minimum production of Pu. In this paper, I will contrast the production of excess carbon in the form of CO 2 from fossil fuels with

  7. Carbon dioxide capture from reforming gases using acetic acid-mixed chemical absorbents

    Energy Technology Data Exchange (ETDEWEB)

    Rahmanian, Amin; Zaini, Muhammad Abbas ahmad; Abdullah, Tuan Amran Tuan [Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Johor Bahru (Malaysia)

    2015-07-15

    Carbon dioxide (CO{sub 2}) is a major problem in the production of natural gas as it may contribute to the operational problems such as foaming, corrosion, high solution viscosity, and fouling, thereby decreasing the plant life. The presence of acid gas in natural gas reforming may also result in the increase of transported gas volume and the decrease of heating value. Absorption using aqueous solutions of alkanolamines has been a preferred approach in current industry for CO{sub 2} removal. Concentration of ammonia and DEA affects the CO{sub 2} removal; increasing the absorbents concentration increases the CO{sub 2} removal. On molar basis, DEA shows a greater CO{sub 2} absorption than ammonia. Acetic acid-mixed absorbents display a lower CO{sub 2} removal than the nonmixed ones. Decrease in solubility due to the decrease in solution pH has resulted in a lower CO{sub 2} absorption by acetic acid-mixed absorbents. Liquid flow rate offers only small influence on the absorption of CO{sub 2}, while decreasing the gas flow rate increases the CO{sub 2} removal. On the operational point of view, blend of ammonia and DEA absorbent would be beneficial for CO{sub 2} removal from reforming gases as it could partly solve the problems associated with regeneration and corrosion.

  8. Catalytic performance of activated carbon supported cobalt catalyst for CO2 reforming of CH4.

    Science.gov (United States)

    Zhang, Guojie; Su, Aiting; Du, Yannian; Qu, Jiangwen; Xu, Ying

    2014-11-01

    Syngas production by CO2 reforming of CH4 in a fixed bed reactor was investigated over a series of activated carbon (AC) supported Co catalysts as a function of Co loading (between 15 and 30wt.%) and calcination temperature (Tc=300, 400 or 500°C). The catalytic performance was assessed through CH4 and CO2 conversions and long-term stability. XRD and SEM were used to characterize the catalysts. It was found that the stability of Co/AC catalysts was strongly dependent on the Co loading and calcination temperature. For the loadings (25wt.% for Tc=300°C), stable activities have been achieved. The loading of excess Co (>wt.% 25) causes negative effects not only on the performance of the catalysts but also on the support surface properties. In addition, the experiment showed that ultrasound can enhance and promote dispersion of the active metal on the carrier, thus improving the catalytic performance of the catalyst. The catalyst activity can be long-term stably maintained, and no obvious deactivation has been observed in the first 2700min. After analyzing the characteristics, a reaction mechanism for CO2 reforming of CH4 over Co/AC catalyst was proposed. Copyright © 2014 Elsevier Inc. All rights reserved.

  9. A low-temperature partial-oxidation-methanol micro reformer with high fuel conversion rate and hydrogen production yield

    International Nuclear Information System (INIS)

    Wang, Hsueh-Sheng; Huang, Kuo-Yang; Huang, Yuh-Jeen; Su, Yu-Chuan; Tseng, Fan-Gang

    2015-01-01

    Highlights: • A low-operating temperature of the POM-mode micro methanol reformer is obtained. • The effect of channel design on the performance is studied. • The effect of solid content and binder’ ratio on the performance is studied. • The centrifugal process is benefit for the modification of performance. • 98% of methanol conversion rate of the micro reformer can be obtained at 180 °C. - Abstract: A partial oxidation methanol micro reformer (POM-μReformer) with finger-shaped channels for low operating temperature and high conversing efficiency is proposed in this study. The micro reformer employs POM reaction for low temperature operation (less than 200 °C), exothermic reaction, and quick start-up, as well as air feeding capability; and the finger type reaction chambers for increasing catalyst loading as well as reaction area for performance enhancement. In this study, centrifugal technique was introduced to assist on the catalyst loading with high amount and uniform distribution. The solid content (S), binder’s ratio (B), and channel design (the ratio between channel’s length and width, R) were investigated in detail to optimize the design parameters. Scanning electron microscopy (SEM), gas chromatography (GC), and inductively coupled plasma-mass spectrometer (ICP-MS) were employed to analyze the performance of the POM-μReformer. The result depicted that the catalyst content and reactive area could be much improved at the optimized condition, and the conversion rate and hydrogen selectivity approached 97.9% and 97.4%, respectively, at a very low operating temperature of 180 °C with scarce or no binder in catalyst. The POM-μReformer can supply hydrogen to fuel cells by generating 2.23 J/min for 80% H 2 utilization and 60% fuel cell efficiency at 2 ml/min of supplied reactant gas, including methanol, oxygen and argon at a mixing ratio of 12.2%, 6.1% and 81.7%, respectively

  10. Mixed fuel strategy for carbon deposition mitigation in solid oxide fuel cells at intermediate temperatures.

    Science.gov (United States)

    Su, Chao; Chen, Yubo; Wang, Wei; Ran, Ran; Shao, Zongping; Diniz da Costa, João C; Liu, Shaomin

    2014-06-17

    In this study, we propose and experimentally verified that methane and formic acid mixed fuel can be employed to sustain solid oxide fuel cells (SOFCs) to deliver high power outputs at intermediate temperatures and simultaneously reduce the coke formation over the anode catalyst. In this SOFC system, methane itself was one part of the fuel, but it also played as the carrier gas to deliver the formic acid to reach the anode chamber. On the other hand, the products from the thermal decomposition of formic acid helped to reduce the carbon deposition from methane cracking. In order to clarify the reaction pathways for carbon formation and elimination occurring in the anode chamber during the SOFC operation, O2-TPO and SEM analysis were carried out together with the theoretical calculation. Electrochemical tests demonstrated that stable and high power output at an intermediate temperature range was well-maintained with a peak power density of 1061 mW cm(-2) at 750 °C. With the synergic functions provided by the mixed fuel, the SOFC was running for 3 days without any sign of cell performance decay. In sharp contrast, fuelled by pure methane and tested at similar conditions, the SOFC immediately failed after running for only 30 min due to significant carbon deposition. This work opens a new way for SOFC to conquer the annoying problem of carbon deposition just by properly selecting the fuel components to realize their synergic effects.

  11. Hydrogen production through allothermal ethanol reforming for fuel cells application: first generation prototype; Producao de hidrogenio atraves da reforma-vapor do etanol para aplicacoes em celulas a combustivel: prototipo de primeira geracao

    Energy Technology Data Exchange (ETDEWEB)

    Marin Neto, Antonio Jose; Silva, Ennio Peres da; Camargo, Joao Carlos; Neves Junior, Newton Pimenta; Pinto, Cristiano da Silva [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Lab. de Hidrogenio; Pinto, Cristiano da Silva [Centro Nacional de Referencia em Energia do Hidrogenio, Campinas, SP (Brazil)

    2004-07-01

    This paper describes preliminary results obtained with the allothermal ethanol reforming system for synthesis gas (syn-gas) production and hydrogen upgrading and purification for fuel cell applications. The system was designed to supply hydrogen to a 500 W PEM (Proton Exchange Membrane) fuel cell, with an electrical efficiency of 45%, which requires approximately 0.45 m3.h-1 of hydrogen, with a maximum carbon monoxide concentration of 20 {mu}mol.mol-1 (ppm). The study was performed changing the operation temperature and analyzing the resulting syn-gas through gas chromatography for a specific catalyst. This catalyst was tested up to 700 deg C, 1 bar and fixed stoichiometric steam to carbon ratio. The syn-gas, before carbon monoxide shift reactor implementation, was submitted to a two-bed-three-segments purification step composed of chemical and physical molecular sieves for hydrogen purification. The carbon monoxide shift reactor (water gas shift reactor) is under development to improve the efficiency-to-hydrogen and maximize the life of the purification bed. The final results also include a discussion about possible reactions involved in ethanol steam-reforming for such catalyst. (author)

  12. Carbon dioxide reforming of methane by atmospheric pressure pulsed glow discharge: The effect of pulse compression

    International Nuclear Information System (INIS)

    Ghorbanzadeh, A.; Modarresi, H.

    2006-01-01

    Methane reforming by carbon dioxide in atmospheric pressure pulsed glow discharge was examined. The pulse duration of plasma was compressed to ∼50 ns or lower. This compression allowed working at higher frequencies, more than 3 k Hz, without glow to arc transition. The main outlet gases were synthetic gases (H 2 , CO) and C 2 (ethylene, ethane, and acetylene) products. At equal reactants proportion CO 2 /CH 4 =1, about 42 p ercent o f plasma energy went to chemical dissociation while reactant conversions were relatively high, i.e. near 55 p ercent % (CH 4 ) and 42 p ercent ( CO 2 ). At this point, the energy expenditure was less than 3.8 eV per each converted molecule. The reactor energy performance even gets better at higher CO 2 /CH 4 proportions. At CO 2 /CH 4 =5, The conversions of about 65 p ercent a nd 45 p ercent w ere obtained for methane and carbon dioxide respectively, while energy efficiency reached near 45 p ercent . It is discussed that high nonequilibrium state of vibrational energy at short pulses, especially in carbon dioxide, leads to this improvement.

  13. Nickel metal with various morphologies: synthesis and performances for catalytic carbon dioxide reforming with methane.

    Science.gov (United States)

    Teabpinyok, Nopporn; Samingprai, Sutheerawat; Chareonpanich, Metta

    2012-12-01

    In this research, nickel metal of three different morphologies including nanostar, icosahedra, and microsphere structures were synthesized. It was found nanostar nickel revealed the Ni(111) crystallographic plane with particle size in the range of 150-200 nm and BET surface area of 13 m2/g. The icosahedra nickel also showed the Ni(111) crystallographic plane with larger particle size (300-400 nm) and BET surface area of 20 m2/g, whereas microsphere nickel exhibited the relatively large cluster size (approximately 3 microm) and BET surface area (114 m2/g) as a result of an aggregation of Ni(101) nanoplates. The obtained nickel catalysts were tested for the activity in carbon dioxide reforming with methane. Based on the similar specific surface area of catalysts, nanostar nickel showed the highest carbon dioxide and methane conversions due to its crystallographic structure. At 700 degrees C, nanostar nickel catalyst exhibited the highest carbon dioxide and methane conversions of 17.6 and 10.5 times higher than those of microsphere nickel catalyst, respectively.

  14. Assessment of technologies to meet a low carbon fuel standard.

    Science.gov (United States)

    Yeh, Sonia; Lutsey, Nicholas P; Parker, Nathan C

    2009-09-15

    California's low carbon fuel standard (LCFS) was designed to incentivize a diverse array of available strategies for reducing transportation greenhouse gas (GHG) emissions. It provides strong incentives for fuels with lower GHG emissions, while explicitly requiring a 10% reduction in California's transportation fuel GHG intensity by 2020. This paper investigates the potential for cost-effective GHG reductions from electrification and expanded use of biofuels. The analysis indicates that fuel providers could meetthe standard using a portfolio approach that employs both biofuels and electricity, which would reduce the risks and uncertainties associated with the progress of cellulosic and battery technologies, feedstock prices, land availability, and the sustainability of the various compliance approaches. Our analysis is based on the details of California's development of an LCFS; however, this research approach could be generalizable to a national U.S. standard and to similar programs in Europe and Canada.

  15. Solid oxide fuel cell technology coupled with methane dry reforming: A viable option for high efficiency plant with reduced CO2 emissions

    International Nuclear Information System (INIS)

    Barelli, L.; Ottaviano, A.

    2014-01-01

    Nowadays the control of greenhouse gas is probably the most challenging environmental policy issue. Since CO 2 is considered the major greenhouse gas (GHG) that contributes to the global warming, enforcing technological strategies aiming to avoid or reuse CO 2 emissions becomes crucial, in order to mitigate GHG environmental impact. Currently, solutions conventionally adopted to this purpose are carbon capture and storage (CCS) technologies. In this context, instead, the followed strategy aims to further improvements in energetic conversion efficiency with related reduced specific CO 2 emissions (per produced kWh e ). Therefore, with particular reference to the electric power generation, this paper proposes an innovative energy conversion system, based on solid oxide fuel cell (SOFC), characterized by higher efficiency and reduced CO 2 emission factor respect to an analogous conventional energy plant. In particular, the innovative solution consists of combining SOFC to methane dry reforming technology, while the conventional system refers to steam methane reforming-SOFC coupling. The innovative system performance up to 65% electric efficiency as cited in the paper, was validated through simulations carried out in Aspen Plus environment. - Highlights: • An innovative high efficiency plant with low CO 2 emissions is presented. • The new solution combined SOFC to methane dry reforming technology (CDR–SOFC). • A comparison between CDR–SOFC and SMR–SOFC system was carried out in Aspen Plus. • CDR–SOFC efficiency is greater of 6.4% percentage points respect to SMR–SOFC. • A CO 2 emission factor reduction of about 10% was achieved by CDR–SOFC plant

  16. PRICE TRANSMISSION AND HOUSEHOLDS DEMAND ELASTICITY FOR FROZEN FISH UNDER FUEL SUBSIDY REFORM IN DELTA STATE, NIGERIA

    Directory of Open Access Journals (Sweden)

    Achoja Felix Odemero

    2013-07-01

    Full Text Available Fuel subsidy removal is assumed to translate to general increase in the cost of operating business such as fish marketing.The response of price of fish and corresponding demand elasticity are welfare issues worthy of investigation in Nigeria. The present study evaluates price transmission in fish marketing system by analysing the response of fish market indices to fuel subsidy reform in Nigeria. Primary data collected with structured questionnaire from purposively selected 78 frozen fish marketers, were analysed with descriptive statistics and regression model. A test of hypothesis shows a significant price transmission of about 100% (P < 0.05. Marketing cost increased by 31.8% and profitability dropped by 24.20%, confirming negative effect of new price regime. The result further revealed a 0.05% drop in quantity of frozen fish demanded by households. It was recommended that economic measures should be introduced by the government to cushion the effect of fuel policy removal.

  17. Process and reactor for the production of hydrogen and carbon dioxide and a fuel cell system

    NARCIS (Netherlands)

    2006-01-01

    The invention relates to a process for the production of hydrogen and carbon dioxide from a hydrocarbonaceous feedstock, comprising: a) supplying a gaseous hydrocarbonaceous feedstock and steam to a reaction zone comprising a steam reforming catalyst and catalytically reforming the hydrocarbonaceous

  18. Effect of inlet fuel type on the degradation of Ni/YSZ anode of solid oxide fuel cell by carbon deposition

    Directory of Open Access Journals (Sweden)

    Suttichai Assabumrungrat

    2006-11-01

    Full Text Available According to the high operating temperature of Solid Oxide Fuel Cell (SOFC (700-1100ºC, it is known that some hydrocarbon fuels can be directly used as inlet fuel instead of hydrogen by feeding straight to the anode. This operation is called a direct internal reforming SOFC (DIR-SOFC. However, the major difficulty of this operation is the possible degradation of anode by the carbon deposition, as the carbon species are easily formed. In the present work, the effect of inlet fuel (i.e. H2, synthesis gas (H2+CO, CH4, CH4+H2O, CH3OH+H2O, and C2H5OH+H2O on the degradation of nickel cermet (Ni/YSZ, which is the most common anode material of SOFC, was studied.It was found from the work that hydrogen and synthesis gas (CO+H2 are proper to be used as direct inlet fuels for DIR-SOFC with Ni/YSZ anode, since the carbon formation on Ni/YSZ occurred in the small quantity. The mixture of methane and steam (CH4+H2O can also be used as the inlet feed, but the H2O/CH4 ratio plays an important role. In contrast, pure methane (CH4, methanol with steam (CH3OH+H2O and ethanol with steam (C2H5OH+H2O are not suitable for using as direct inlet fuel for DIR-SOFC with Ni/YSZ anode even the higher H2O/CH3OH and H2O/C2H5OH ratios were applied.

  19. Fossil fuel derivatives with reduced carbon. Phase I final report

    Energy Technology Data Exchange (ETDEWEB)

    Kennel, E.B.; Zondlo, J.W.; Cessna, T.J.

    1999-06-30

    This project involves the simultaneous production of clean fossil fuel derivatives with reduced carbon and sulfur, along with value-added carbon nanofibers. This can be accomplished because the nanofiber production process removes carbon via a catalyzed pyrolysis reaction, which also has the effect of removing 99.9% of the sulfur, which is trapped in the nanofibers. The reaction is mildly endothermic, meaning that net energy production with real reductions in greenhouse emissions are possible. In Phase I research, the feasibility of generating clean fossil fuel derivatives with reduced carbon was demonstrated by the successful design, construction and operation of a facility capable of utilizing coal as well as natural gas as an inlet feedstock. In the case of coal, for example, reductions in CO{sub 2} emissions can be as much as 70% (normalized according to kilowatts produced), with the majority of carbon safely sequestered in the form of carbon nanofibers or coke. Both of these products are value-added commodities, indicating that low-emission coal fuel can be done at a profit rather than a loss as is the case with most clean-up schemes. The main results of this project were as follows: (1) It was shown that the nanofiber production process produces hydrogen as a byproduct. (2) The hydrogen, or hydrogen-rich hydrocarbon mixture can be consumed with net release of enthalpy. (3) The greenhouse gas emissions from both coal and natural gas are significantly reduced. Because coal consumption also creates coke, the carbon emission can be reduced by 75% per kilowatt-hour of power produced.

  20. CFD analysis of a solid oxide fuel cell with internal reforming: Coupled interactions of transport, heterogeneous catalysis and electrochemical processes

    Science.gov (United States)

    Janardhanan, Vinod M.; Deutschmann, Olaf

    Direct internal reforming in solid oxide fuel cell (SOFC) results in increased overall efficiency of the system. Present study focus on the chemical and electrochemical process in an internally reforming anode supported SOFC button cell running on humidified CH 4 (3% H 2 O). The computational approach employs a detailed multi-step model for heterogeneous chemistry in the anode, modified Butler-Volmer formalism for the electrochemistry and Dusty Gas Model (DGM) for the porous media transport. Two-dimensional elliptic model equations are solved for a button cell configuration. The electrochemical model assumes hydrogen as the only electrochemically active species. The predicted cell performances are compared with experimental reports. The results show that model predictions are in good agreement with experimental observation except the open circuit potentials. Furthermore, the steam content in the anode feed stream is found to have remarkable effect on the resulting overpotential losses and surface coverages of various species at the three-phase boundary.

  1. Study of different nanostructured carbon supports for fuel cell catalysts

    Science.gov (United States)

    Mirabile Gattia, Daniele; Antisari, Marco Vittori; Giorgi, Leonardo; Marazzi, Renzo; Piscopiello, Emanuela; Montone, Amelia; Bellitto, Serafina; Licoccia, Silvia; Traversa, Enrico

    Pt clusters were deposited by an impregnation process on three carbon supports: multi-wall carbon nanotubes (MWNT), single-wall carbon nanohorns (SWNH), and Vulcan XC-72 carbon black to investigate the effect of the carbon support structure on the possibility of reducing Pt loading on electrodes for direct methanol (DMFC) fuel cells without impairing performance. MWNT and SWNH were in-house synthesised by a DC and an AC arc discharge process between pure graphite electrodes, respectively. UV-vis spectrophotometry, scanning and transmission electron microscopy, X-ray diffraction, and cyclic voltammetry measurements were used to characterize the Pt particles deposited on the three carbon supports. A differential yield for Pt deposition, not strictly related to the surface area of the carbon support, was observed. SWNH showed the highest surface chemical activity toward Pt deposition. Pt deposited in different forms depending on the carbon support. Electrochemical characterizations showed that the Pt nanostructures deposited on MWNT are particularly efficient in the methanol oxidation reaction.

  2. Performance analysis of a SOFC under direct internal reforming conditions

    Energy Technology Data Exchange (ETDEWEB)

    Janardhanan, Vinod M.; Deutschmann, Olaf [Institute for Chemical Technology and Polymer Chemistry, Engesserstr 20, D-76131 Karlsruhe, University of Karlsruhe (Germany); Heuveline, Vincent [Institute for Applied and Numerical Mathematics, Kaiserstr. 12, D-76128 Karlsruhe (Germany)

    2007-10-11

    This paper presents the performance analysis of a planar solid-oxide fuel cell (SOFC) under direct internal reforming conditions. A detailed solid-oxide fuel cell model is used to study the influences of various operating parameters on cell performance. Significant differences in efficiency and power density are observed for isothermal and adiabatic operational regimes. The influence of air number, specific catalyst area, anode thickness, steam to carbon (s/c) ratio of the inlet fuel, and extend of pre-reforming on cell performance is analyzed. In all cases except for the case of pre-reformed fuel, adiabatic operation results in lower performance compared to isothermal operation. It is further discussed that, though direct internal reforming may lead to cost reduction and increased efficiency by effective utilization of waste heat, the efficiency of the fuel cell itself is higher for pre-reformed fuel compared to non-reformed fuel. Furthermore, criteria for the choice of optimal operating conditions for cell stacks operating under direct internal reforming conditions are discussed. (author)

  3. Performance analysis of a SOFC under direct internal reforming conditions

    Science.gov (United States)

    Janardhanan, Vinod M.; Heuveline, Vincent; Deutschmann, Olaf

    This paper presents the performance analysis of a planar solid-oxide fuel cell (SOFC) under direct internal reforming conditions. A detailed solid-oxide fuel cell model is used to study the influences of various operating parameters on cell performance. Significant differences in efficiency and power density are observed for isothermal and adiabatic operational regimes. The influence of air number, specific catalyst area, anode thickness, steam to carbon (s/c) ratio of the inlet fuel, and extend of pre-reforming on cell performance is analyzed. In all cases except for the case of pre-reformed fuel, adiabatic operation results in lower performance compared to isothermal operation. It is further discussed that, though direct internal reforming may lead to cost reduction and increased efficiency by effective utilization of waste heat, the efficiency of the fuel cell itself is higher for pre-reformed fuel compared to non-reformed fuel. Furthermore, criteria for the choice of optimal operating conditions for cell stacks operating under direct internal reforming conditions are discussed.

  4. Processing real-world waste plastics by pyrolysis-reforming for hydrogen and high-value carbon nanotubes.

    Science.gov (United States)

    Wu, Chunfei; Nahil, Mohamad A; Miskolczi, Norbert; Huang, Jun; Williams, Paul T

    2014-01-01

    Producing both hydrogen and high-value carbon nanotubes (CNTs) derived from waste plastics is reported here using a pyrolysis-reforming technology comprising a two-stage reaction system, in the presence of steam and a Ni-Mn-Al catalyst. The waste plastics consisted of plastics from a motor oil container (MOC), commercial waste high density polyethylene (HDPE) and regranulated HDPE waste containing polyvinyl chloride (PVC). The results show that hydrogen can be produced from the pyrolysis-reforming process, but also carbon nanotubes are formed on the catalyst. However, the content of 0.3 wt.% polyvinyl chloride in the waste HDPE (HDPE/PVC) has been shown to poison the catalyst and significantly reduce the quantity and purity of CNTs. The presence of sulfur has shown less influence on the production of CNTs in terms of quantity and CNT morphologies. Around 94.4 mmol H2 g(-1) plastic was obtained for the pyrolysis-reforming of HDPE waste in the presence of the Ni-Mn-Al catalyst and steam at a reforming temperature of 800 °C. The addition of steam in the process results in an increase of hydrogen production and reduction of carbon yield; in addition, the defects of CNTs, for example, edge dislocations were found to be increased with the introduction of steam (from Raman analysis).

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

    Science.gov (United States)

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

    2017-10-01

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

  6. Electrolyte matrix for molten carbonate fuel cells

    Science.gov (United States)

    Huang, C.M.; Yuh, C.Y.

    1999-02-09

    A matrix is described for a carbonate electrolyte including a support material and an additive constituent having a relatively low melting temperature and a relatively high coefficient of thermal expansion. The additive constituent is from 3 to 45 weight percent of the matrix and is formed from raw particles whose diameter is in a range of 0.1 {micro}m to 20 {micro}m and whose aspect ratio is in a range of 1 to 50. High energy intensive milling is used to mix the support material and additive constituent during matrix formation. Also disclosed is the use of a further additive constituent comprising an alkaline earth containing material. The further additive is mixed with the support material using high energy intensive milling. 5 figs.

  7. Electrolyte matrix for molten carbonate fuel cells

    Science.gov (United States)

    Huang, Chao M.; Yuh, Chao-Yi

    1999-01-01

    A matrix for a carbonate electrolyte including a support material and an additive constituent having a relatively low melting temperature and a relatively high coefficient of thermal expansion. The additive constituent is from 3 to 45 weight percent of the matrix and is formed from raw particles whose diameter is in a range of 0.1 .mu.m to 20 .mu.m and whose aspect ratio is in a range of 1 to 50. High energy intensive milling is used to mix the support material and additive constituent during matrix formation. Also disclosed is the use of a further additive constituent comprising an alkaline earth containing material. The further additive is mixed with the support material using high energy intensive milling.

  8. HTGR fuel rods: carbon-carbon composites designed for high weight and low strength

    International Nuclear Information System (INIS)

    Bullock, R.E.

    1977-01-01

    The evolution of the process for fabricating fuel rods for the high-temperature gas-cooled reactor (HTGR) by injection and carbonization of a thermoplastic matrix that bonds close-packed beds of pyrocarbon-coated fuel particles together is reviewed for the fresh-fuel cycle, and a variant process involving a thermosetting matrix that would allow free-standing carbonization of refabricated fuel is discussed. Previous attempts to fabricate such injection-bonded fuel rods from undiluted thermosetting binders filled with powdered graphite were unsuccessful, because of damage to coatings on fuel particles that resulted from strong particle-to-matrix bonding in conjunction with large matrix shrinkage on carbonization and subsequent irradiation. These problems have now been overcome through the use of a diluted thermosetting matrix with a low-char-yield additive (fugitive), which produces a more porous char similar to that from the pitch-based thermoplastic used in fabrication of fresh fuel. A 1-to-1 dilution of resin with fugitive produced the optimum binder for injection and carbonization, where the fired matrix in such rods contained about 20 wt% binder char and 80 wt% powdered graphite. Thermosetting fuel rods diluted with various amounts of fugitive to give binder chars that range from 12 to 48 wt% of the fired matrix have been subjected to irradiation screening tests, and rods with no more than 32 wt% binder char appear to perform about as well under irradiation as do pitch-based rods. However, particle damage does begin to occur in those lightly diluted rods in which the less-stable binder char constitutes more than 32 wt% of the fired matrix. (author)

  9. Fuel oil from low-temperature carbonization of coal

    Energy Technology Data Exchange (ETDEWEB)

    Thau, A

    1941-01-01

    A review has been given of German developments during the last 20 years. Four methods for the low-temperature carbonization of coal have been developed to the industrial stage; two involving the use of externally heated, intermittent, metallic chamber ovens; and two employing the principle of internal heating by means of a current of gas. Tar from externally heated retorts can be used directly as fuel oil, but that from internally heated retorts requires further treatment. In order to extend the range of coals available for low-temperature carbonization, and to economize metals, an externally heated type of retort constructed of ceramic material has been developed to the industrial stage by T. An excellent coke and a tar that can be used directly as fuel oil are obtained. The properties of the tar obtained from Upper Silesian coal are briefly summarized.

  10. Manufacturing method of molten carbonate fuel cell. Yoyu tansan prime en nenryo denchi no seizo hoho

    Energy Technology Data Exchange (ETDEWEB)

    Muneuchi, Atsuo; Murata, Kenji

    1989-09-14

    An fuel electrode of a molten carbonate fuel cell is preliminarily dipped with molten carbonate. This operation is troublesome and reduces the productivity because this operation is made by the fuel electrode unit. In this invention, the carbonate is dipped in the process of temperature elevation after the assembly of the fuel cell. In other words, the carbonate electrode is buried in a groove formed in the fuel electrode leaving a gas flowing space; this fuel electrode is layer-built with a matrix and an oxidant electrode to form a unit cell; this unit cell is assembled to compose a fuel cell; while an anti-oxidant gas is fed to a groove of the fuel electrode, temperature is raised up to the operation level, wherein the carbonnate in the groove is molten to be dipped into the fuel electrode. The anti-oxidant gas is such inactive ones as carbon dioxide, nitrogen, argon and helium. 2 figs.

  11. Molten carbonate fuel cell cathode with mixed oxide coating

    Science.gov (United States)

    Hilmi, Abdelkader; Yuh, Chao-Yi

    2013-05-07

    A molten carbonate fuel cell cathode having a cathode body and a coating of a mixed oxygen ion conductor materials. The mixed oxygen ion conductor materials are formed from ceria or doped ceria, such as gadolinium doped ceria or yttrium doped ceria. The coating is deposited on the cathode body using a sol-gel process, which utilizes as precursors organometallic compounds, organic and inorganic salts, hydroxides or alkoxides and which uses as the solvent water, organic solvent or a mixture of same.

  12. Monthly, global emissions of carbon dioxide from fossil fuel consumption

    Energy Technology Data Exchange (ETDEWEB)

    Andres, R. J.; Marland, G.; Boden, T. A. (Environmental Sciences Div., Oak Ridge National Laboratory, Oak Ridge, TN (United States)), e-mail: andresrj@ornl.gov; Gregg, J. S. (Risoe DTU National Laboratory for Sustainable Energy, Roskilde (Denmark)); Losey, L. (Dept. of Space Studies, Univ. of North Dakota, Grand Forks, ND (United States))

    2011-07-15

    This paper examines available data, develops a strategy and presents a monthly, global time series of fossil-fuel carbon dioxide emissions for the years 1950-2006. This monthly time series was constructed from detailed study of monthly data from the 21 countries that account for approximately 80% of global total emissions. These data were then used in a Monte Carlo approach to proxy for all remaining countries. The proportional-proxy methodology estimates by fuel group the fraction of annual emissions emitted in each country and month. Emissions from solid, liquid and gas fuels are explicitly modelled by the proportional-proxy method. The primary conclusion from this study is the global monthly time series is statistically significantly different from a uniform distribution throughout the year. Uncertainty analysis of the data presented show that the proportional-proxy method used faithfully reproduces monthly patterns in the data and the global monthly pattern of emissions is relatively insensitive to the exact proxy assignments used. The data and results presented here should lead to a better understanding of global and regional carbon cycles, especially when the mass data are combined with the stable carbon isotope data in atmospheric transport models

  13. Energy Analysis in Combined Reforming of Propane

    Directory of Open Access Journals (Sweden)

    K. Moon

    2013-01-01

    Full Text Available Combined (steam and CO2 reforming is one of the methods to produce syngas for different applications. An energy requirement analysis of steam reforming to dry reforming with intermediate steps of steam reduction and equivalent CO2 addition to the feed fuel for syngas generation has been done to identify condition for optimum process operation. Thermodynamic equilibrium data for combined reforming was generated for temperature range of 400–1000°C at 1 bar pressure and combined oxidant (CO2 + H2O stream to propane (fuel ratio of 3, 6, and 9 by employing the Gibbs free energy minimization algorithm of HSC Chemistry software 5.1. Total energy requirement including preheating and reaction enthalpy calculations were done using the equilibrium product composition. Carbon and methane formation was significantly reduced in combined reforming than pure dry reforming, while the energy requirements were lower than pure steam reforming. Temperatures of minimum energy requirement were found in the data analysis of combined reforming which were optimum for the process.

  14. Thermodynamic evaluation of hydrogen production for fuel cells by using bio-ethanol steam reforming: Effect of carrier gas addition

    Science.gov (United States)

    Hernández, Liliana; Kafarov, Viatcheslav

    Omitting the influence of the addition of carrier gas to the reaction system for hydrogen production by bio-ethanol steam reforming can lead to wrong conclusions, especially when it is going to be made to scale. The effect of carrier gas addition to produce hydrogen using bio-ethanol steam reforming to feed fuel cells was evaluated. Thermodynamic calculations in equilibrium conditions were made, however the analysis derived from them can also be applied to kinetic conditions. These calculations were made by using the Aspen-HYSYS software at atmospheric pressure and different values of temperature, water/ethanol molar ratios, and inert (argon)/(water/ethanol) molar ratios. The addition of inert carrier gas modifies the concentrations of the reaction products in comparison to those obtained without its presence. This behavior occurs because most of the reactions which take place in bio-ethanol steam reforming have a positive difference of moles. This fact enhances the system sensitivity to inert concentration at low and moderated temperatures (<700 °C). At high values of temperature, the inert addition does not influence the composition of the reaction products because of the predominant effect of inverse WGS reaction.

  15. Thermodynamic evaluation of hydrogen production for fuel cells by using bio-ethanol steam reforming: Effect of carrier gas addition

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez, Liliana; Kafarov, Viatcheslav [Universidad Industrial de Santander, Escuela de Ingenieria Quimica, Bucaramanga 678 (Colombia)

    2009-07-01

    Omitting the influence of the addition of carrier gas to the reaction system for hydrogen production by bio-ethanol steam reforming can lead to wrong conclusions, especially when it is going to be made to scale. The effect of carrier gas addition to produce hydrogen using bio-ethanol steam reforming to feed fuel cells was evaluated. Thermodynamic calculations in equilibrium conditions were made, however the analysis derived from them can also be applied to kinetic conditions. These calculations were made by using the Aspen-HYSYS software at atmospheric pressure and different values of temperature, water/ethanol molar ratios, and inert (argon)/(water/ethanol) molar ratios. The addition of inert carrier gas modifies the concentrations of the reaction products in comparison to those obtained without its presence. This behavior occurs because most of the reactions which take place in bio-ethanol steam reforming have a positive difference of moles. This fact enhances the system sensitivity to inert concentration at low and moderated temperatures (<700 C). At high values of temperature, the inert addition does not influence the composition of the reaction products because of the predominant effect of inverse WGS reaction. (author)

  16. Heat balance of a molten carbonate fuel cell production hydrogen for a polymer electrolyte fuel cell-CoCell; Waermehaushalt einer Karbonat-Brennstoffzelle zur Wasserstoffherstellung fuer eine Polymerelektrolyt-Brennstoffzelle

    Energy Technology Data Exchange (ETDEWEB)

    Adamek, L.

    2006-10-17

    Molten carbonate fuel cells (MCFC) are being used in decentralised power plants, as they can reform hydrocarbon bound fuels internally, e.g. natural gas with a energy density of 10 kWh/m{sup 3} at standard conditions, and the efficiency of this mode of operation is around 50 %. However in comparison to other fuel cell systems the power density is only 5 kW/m{sup 3}. The power density of a polymerelectrolyte fuel cell (PEFC) is much higher (50 kW/m{sup 3}). These systems can be run with an efficiency of 50 %, too. Therefore they need hydrogen as a fuel, with an energy density of 2,9 kWh/m{sup 3} at standard conditions. Efficiency decreases to 35 to 40% using Methane as fuel, because of the reforming losses. The power density than is 6 kW/m3 and therefore as high as for a MCFC-system. Acombination of MCFC and PEFC, the so called CoCell, offers the following advantages: - A highly energetic, hydrocarbon based fuel can be used, e.g. Methane. - A high electrical efficiency is achieved. - The power density of this system is higher than for a fuel cell with reformer. In the CoCell the MCFC is working as electricity producing reformer for the PEFC. The off heat of the MCFC is used for reforming, whereby hydrogen is available, being utilised further in the power dense PEFC. The reforming capacity of the MCFC is limited by the internal heat balance. If the endothermic reforming consumes more heat than supplied by the material streams and the fuel cell waste heat, the stack cools down. The performance of such a combined fuel cell system has been evaluated in this thesis using the thermodynamic simulation software Aspen. Calculations reducing the utilisation in the MCFC by various heating techniques showed, that additional heat is supplied most efficiently by increasing the current density of the MCFC. Thereby the stack is heated electrically and the power density of the system is increased by the improved power density of the MCFC. The reduction of the utilisation is achieved

  17. Hibiscus fiber carbon for fuel cell device material

    International Nuclear Information System (INIS)

    Nanik Indayaningsih; Anne Zulfia; Dedi Priadi; Suprapedi

    2010-01-01

    The objective of this research is carbon of hibiscus fibers for the application as basic material of fuel cell device. The carbon is made using a pyrolysis process in inert gas (nitrogen) for 1 hour at temperature of 500 °C, 700 °C and 900 °C. The X-Ray Diffractometer (XRD), Scanning Electron Microscope (SEM) and Impedance-Capacitance-Resistance-meter are used to find out the microstructure, morphology and electrical properties respectively. The results of the experiment showed that the carbon had a structure of amorphous, and as the semiconductor material the electrical conductivity was 5 x 10"-"5 S.cm"-"1 to 4.9 x 10"-"5 S.cm"-"1 increasing in accordance with the pyrolysis temperature. The morphology resembled to plaited mats constructed by porous fibers having width of 50 µm to 300 µm, thickness of 25 µm to 35 µm, and the porous size of 0.5 µm to 5 µm. This morphology enables carbon to be applied as a candidate for a basic material of the Proton Exchange Membrane Fuel Cell. (author)

  18. Investigation of chemical and electrochemical reactions mechanisms in a direct carbon fuel cell using olive wood charcoal as sustainable fuel

    Science.gov (United States)

    Elleuch, Amal; Halouani, Kamel; Li, Yongdan

    2015-05-01

    Direct carbon fuel cell (DCFC) is a high temperature fuel cell using solid carbon as fuel. The use of environmentally friendly carbon material constitutes a promising option for the DCFC future. In this context, this paper focuses on the use of biomass-derived charcoal renewable fuel. A practical investigation of Tunisian olive wood charcoal (OW-C) in planar DCFCs is conducted and good power density (105 mW cm-2) and higher current density (550 mA cm-2) are obtained at 700 °C. Analytical and predictive techniques are performed to explore the relationships between fuel properties and DCFC chemical and electrochemical mechanisms. High carbon content, carbon-oxygen groups and disordered structure, are the key parameters allowing the achieved good performance. Relatively complex chain reactions are predicted to explain the gas evolution within the anode. CO, H2 and CH4 participation in the anodic reaction is proved.

  19. Pyrolytic carbon coatings for nuclear fuels from commercial butane

    International Nuclear Information System (INIS)

    Abdelrazek, I.D.; Abdelhalim, A.S.

    1976-01-01

    Uranium dioxide and graphite semi-spherical particles (average diameter = 300 um) were coated with pyrolytic carbon at relatively low temperatures (800 to 1200 0 C). The spouting gas was a mixture of commercial butane and nitrogen. The hydrocarbon served as a source for carbon whereas nitrogenated as a diluent and a support for the bed. The total gas flow rate was 3.5 lit/min and the hydrocarbon content varied from 3 to 10%. Coating efficiencies ranging from 4 to 25 percent were obtained. The densities of the coatings varied from 1.25 g/cm 3 (which corresponds to coatings of laminar microstructures) and 1.82 g/cm 3 (which suggests the formation of isotropic coatings. Metallographic examination (using polarized light) of the pyrolytic carbon formed at the experimental conditions indicated the possibility of using the coatings for nuclear fuel applications

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

    Energy Technology Data Exchange (ETDEWEB)

    Recknagle, Kurtis P.; Ryan, Emily M.; Koeppel, Brian J.; Mahoney, Lenna A.; Khaleel, Moe A. [Pacific Northwest National Laboratory, Richland, WA 99352 (United States)

    2010-10-01

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

  1. A Phenomenological Study on the Synergistic Role of Precious Metals in the Steam Reforming of Logistic Fuels on Bimetal-Supported Catalysts

    Directory of Open Access Journals (Sweden)

    Abdul-Majeed Azad

    2011-01-01

    Full Text Available Fuel processors are required to convert sulfur-laden logistic fuels into hydrogen-rich reformate and deliver to the fuel cell stack with little or no sulfur. Since sulfur poisons and deactivates the reforming catalyst, robust sulfur-tolerant catalysts ought to be developed. In this paper, the development, characterization and evaluation of a series of reforming catalysts containing two noble metals (with total metal loading not exceeding 1 weight percent supported on nanoscale ceria for the steam-reforming of kerosene is reported. Due to inherent synergy, a bimetallic catalyst is superior to its monometallic analog, for the same level of loading. The choice of noble metal combination in the bimetallic formulations plays a vital and meaningful role in their performance. Presence of ruthenium and/or rhodium in formulations containing palladium showed improved sulfur tolerance and significant enhancement in their catalytic activity and stability. Rhodium was responsible for higher hydrogen yields in the logistic fuel reformate. Duration of steady hydrogen production was higher in the case of RhPd (75 h than for RuPd (68 h; hydrogen generation was stable over the longest period (88 h with RuRh containing no Pd. A mechanistic correlation between the characteristic role of precious metals in the presence of each other is discussed.

  2. Steam reforming of cyclic model compounds of bio-oil over Ni-based catalysts: Product distribution and carbon formation

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Jensen, Anker Degn

    2015-01-01

    Steam reforming (SR) and oxidative steam reforming (OSR) of furfural, 2-methylfuran, and guaiacol have been investigated in the temperature range 400-800°C at a steam to carbon (S/C)-ratio of 5 and oxygen to carbon (O/C)-ratio of 0.2-1.4 over Ni/CeO2-K/MgAl2O4. Carbon oxides and H2 were the major...... products in the SR of 2-methylfuran and furfural, while the by-products were methane, ethanol, 2-propanol, and acetone. Temperatures of 500°C or above were needed to minimize the formation of by-products in the SR of 2-methylfuran and furfural. Phenolics, like benzenediols and phenol, were produced in high...... yields in the SR of guaiacol and temperatures of 780°C were needed to totally convert guaiacol to carbon oxides and H2.Carbon deposition was observed in the SR of all three model compounds and was most severe for guaiacol followed by furfural and 2-methylfuran. The carbon deposition could be reduced...

  3. Effects of fuel treatments on carbon-disturbance relationships in forests of the northern Rocky Mountains

    Science.gov (United States)

    Elizabeth Reinhardt; Lisa Holsinger

    2010-01-01

    Fuel treatments alter conditions in forested stands at the time of the treatment and subsequently. Fuel treatments reduce on-site carbon and also change the fire potential and expected outcome of future wildfires, including their carbon emissions. We simulated effects of fuel treatments on 140 stands representing seven major habitat type groups of the northern Rocky...

  4. Reviewing tax system and its reform plan for the fuel market in South Korea

    International Nuclear Information System (INIS)

    Myung-Kyoon Lee

    2005-01-01

    After a long period of government intervention in the energy market, the Korean government has realized that the costs of its intervention are greater than the benefit as the economy got more complicated and more integrated into the world economy. The objective of the energy tax reform is to establish a transparent set of taxing principles, in order to internalize externalities from energy consumption. The expected effects of the reform is to motivate energy conservation and to promote R and D on energy conservation technologies which will ultimately result in the strengthening of industrial competitiveness and the reduction of urban air pollution. (author)

  5. Reviewing tax system and its reform plan for the fuel market in South Korea

    International Nuclear Information System (INIS)

    Lee, M.-K.

    2005-01-01

    After a long period of government intervention in the energy market, the Korean government has realized that the costs of its intervention are greater than the benefit as the economy got more complicated and more integrated into the world economy. The objective of the energy tax reform is to establish a transparent set of taxing principles, in order to internalize externalities from energy consumption. The expected effects of the reform is to motivate energy conservation and to promote R and D on energy conservation technologies which will ultimately result in the strengthening of industrial competitiveness and the reduction of urban air pollution

  6. Expedient Prediction of the Fuel Properties of Carbonized Woody Biomass Based on Hue Angle

    Directory of Open Access Journals (Sweden)

    Yuta Saito

    2018-05-01

    Full Text Available Woody biomass co-firing-based power generation can reduce CO2 emissions from pulverized coal boilers. Carbonization of woody biomass increases its calorific value and grindability, thereby improving the co-firing ratio. Carbonized biomass fuel properties depend on moisture, size and shape of feedstock, and carbonization conditions. To produce carbonized biomass with stable fuel properties, the carbonization conditions should be set according to the desired fuel properties. Therefore, we examined color changes accompanying woody biomass carbonization and proposed using them for rapid evaluation of fuel properties. Three types of woody biomasses were carbonized at a test facility with a capacity of 4 tons/day, and the fuel properties of the obtained materials were correlated with their color defined by the L*a*b* model. When fixed carbon, an important fuel property for carbonization, was 25 wt % or less, we observed a strong negative correlation, regardless of the tree species, between the hue angle, hab, and fixed carbon. The hab and fixed carbon were correlated even when the fixed carbon exceeded 25 wt %; however, this correlation was specific to the tree species. These results indicate that carbonized biomass fuel properties such as fixed carbon can be estimated rapidly and easily by measuring hab.

  7. Steam reforming of commercial ultra-low sulphur diesel

    Energy Technology Data Exchange (ETDEWEB)

    Boon, J.; Van Dijk, E.; De Munck, S.; Van den Brink, R. [Energy research Centre of The Netherlands, ECN Hydrogen and Clean Fossil Fuels, P.O. Box 1, NL1755ZG Petten (Netherlands)

    2011-03-11

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

  8. Steam reforming of commercial ultra-low sulphur diesel

    Science.gov (United States)

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

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

  9. Reducing the carbon footprint of fuels and petrochemicals. Preprints

    International Nuclear Information System (INIS)

    Ernst, S.; Balfanz, U.; Buchholz, S.; Lichtscheidl, J.; Marchionna, M.; Nees, F.; Santacesaria, E.

    2012-01-01

    Within the DGMK conference between 08th and 10th October, 2012, in Berlin (Federal Republic of Germany) the following lectures were held: (1) Energy demand and mix for global welfare and stable ecosystems (A. Jess); (2) The EU's roadmap for moving to a low-carbon economy - Aspirations and reality for refiners (J. Lichtscheidl); (3) Applications of CCS technology to the oil and gas industries (M. Marchionna); (4) A new chemical system solution for acid gas removal (M. Seiler); (5) Hydrogenation of carbon dioxide towards synthetic natural gas - A route to effective future energy storage (M. Schoder); (6) Bio-MTBE - How to reduce CO 2 footprint in fuels with a well known premium gasoline component (O. Busch); (7) Use of waste materials for Biodiesel production (R. Vitiello); (8) From algae to diesel and kerosene - Tailored fuels via selective catalysis (C. Zhao); (9) Chemo-catalytic valorization of cellulose (R. Palkovits); (10) Cellulosic ethanol: Potential, technology and development status (M. Rarbach); (11) Methanation of carbon oxides - History, status quo and future perspectives (W. Kaltner); (12) Chemical storage of renewable electricity in hydrocarbon fuels via H 2 (H. Eilers); (13) Materials for the 21st century: Can the carbon come from CO 2 (S. Kissling); (14) Effect of CO 2 admixture on the catalytic performance of Ni-Nb-M-O catalysts in oxidative dehydrogenation of ethane to ethylene (A. Qiao); (15) Oxidative dehydrogenation of light alkanes (A. Meiswinkel); (16) Low carbon fuel and chemical production from waste gases (S. Simpson); (17) Methanol to propylene: From development to commercialization (S. Haag); (18) On the impact of olefins and aromatics in the methanol-to-hydrocarbon conversion over H-ZSM-5 catalysts (X. Sun); (19) Mn-Na 2 WO 4 /SiO 2 - An industrial catalyst for methane coupling (M. Yildiz); (20) Biorefineries - Prerequisites for the realization of a future bioeconomy (K. Wagemann); (21) A new process for the valorisation of a bio

  10. Reducing the carbon footprint of fuels and petrochemicals. Preprints

    Energy Technology Data Exchange (ETDEWEB)

    Ernst, S.; Balfanz, U.; Buchholz, S.; Lichtscheidl, J.; Marchionna, M.; Nees, F.; Santacesaria, E. (eds.)

    2012-07-01

    Within the DGMK conference between 08th and 10th October, 2012, in Berlin (Federal Republic of Germany) the following lectures were held: (1) Energy demand and mix for global welfare and stable ecosystems (A. Jess); (2) The EU's roadmap for moving to a low-carbon economy - Aspirations and reality for refiners (J. Lichtscheidl); (3) Applications of CCS technology to the oil and gas industries (M. Marchionna); (4) A new chemical system solution for acid gas removal (M. Seiler); (5) Hydrogenation of carbon dioxide towards synthetic natural gas - A route to effective future energy storage (M. Schoder); (6) Bio-MTBE - How to reduce CO{sub 2} footprint in fuels with a well known premium gasoline component (O. Busch); (7) Use of waste materials for Biodiesel production (R. Vitiello); (8) From algae to diesel and kerosene - Tailored fuels via selective catalysis (C. Zhao); (9) Chemo-catalytic valorization of cellulose (R. Palkovits); (10) Cellulosic ethanol: Potential, technology and development status (M. Rarbach); (11) Methanation of carbon oxides - History, status quo and future perspectives (W. Kaltner); (12) Chemical storage of renewable electricity in hydrocarbon fuels via H{sub 2} (H. Eilers); (13) Materials for the 21st century: Can the carbon come from CO{sub 2} (S. Kissling); (14) Effect of CO{sub 2} admixture on the catalytic performance of Ni-Nb-M-O catalysts in oxidative dehydrogenation of ethane to ethylene (A. Qiao); (15) Oxidative dehydrogenation of light alkanes (A. Meiswinkel); (16) Low carbon fuel and chemical production from waste gases (S. Simpson); (17) Methanol to propylene: From development to commercialization (S. Haag); (18) On the impact of olefins and aromatics in the methanol-to-hydrocarbon conversion over H-ZSM-5 catalysts (X. Sun); (19) Mn-Na{sub 2}WO{sub 4}/SiO{sub 2} - An industrial catalyst for methane coupling (M. Yildiz); (20) Biorefineries - Prerequisites for the realization of a future bioeconomy (K. Wagemann); (21) A new process

  11. Fire suppression and fuels treatment effects on mixed-conifer carbon stocks and emissions

    Science.gov (United States)

    M. North; M Hurteau; J Innes

    2009-01-01

    Depending on management, forests can be an important sink or source of carbon that if released as CO2 could contribute to global warming. Many forests in the western United States are being treated to reduce fuels, yet the effects of these treatments on forest carbon are not well understood. We compared the immediate effects of fuels treatments on carbon stocks and...

  12. System requirements of diesel reforming for the SOFC

    International Nuclear Information System (INIS)

    Harasti, P.T.; Amphlett, J.C.; Mann, R.F.; Peppley, B.A.; Thurgood, C.P.

    2003-01-01

    Diesel fuels are currently a very attractive source of hydrogen due to the global infrastructure for production and distribution that exists today. In order to extract the hydrogen, the hydrocarbon molecules must be chemically reformed into manageable, hydrogen-rich product gases that can be directly used in electrochemical energy conversion devices such as fuel cells. High temperature fuel cells are particularly attractive for diesel-fuelled systems due to the possibility of thermal integration with the high temperature reformer. The methods available for diesel fuel processing are: Steam Reforming, Partial Oxidation, and Auto-Thermal Reforming. The latter two methods introduce air into the process in order to cause exothermic oxidation reactions, which complement the endothermic heating requirement of the reforming reactions. This helps to achieve the high temperature required, but also introduces nitrogen, which can yield unwanted NO x emissions. The components of the reformer should include: an injection system to mix and vaporize the diesel fuel and steam while avoiding the formation of carbon deposits inside the reactor; a temperature and heat management system; and a method of sulphur removal. This presentation will discuss the operating conditions and design requirements of a diesel fuel processor for a solid oxide fuel cell (SOFC) system. (author)

  13. Pd-Ag membrane reactor for steam reforming reactions: a comparison between different fuels

    NARCIS (Netherlands)

    Gallucci, F.; Basile, A.

    2008-01-01

    The simulation of a dense Pd-based membrane reactor for carrying out the methane, the methanol and the ethanol steam reforming (SR) reactions for pure hydrogen production is performed. The same simulation is also performed in a traditional reactor. This modelling work shows that the use of membrane

  14. Biomass fuels - effects on the carbon dioxide budget

    International Nuclear Information System (INIS)

    Eriksson, H.; Hallsby, G.

    1992-02-01

    It is highly desirable that the effects on the carbon dioxide balance of alternative energy sources are evaluated. Two important alternatives studied in Sweden are the extraction of logging residues left in the forest and willow production on farmland. Considered in isolation, a conversion from stem-wood harvest to whole-tree harvest has a negative effect on the carbon dioxide balance, because the amount of soil organic matter decreases. With the assumption that it takes 20 years for the logging residues to decompose, the net decrease in emissions that would result from the replacement of fossil fuels by logging residues appear moderate after 20 years. However, it will grow significantly as time passes. After 100 years with an annual combustion of logging residues the emissions are 12% of those associated with the production of an equivalent amount of energy through oil combustion. Corresponding values for 300 and 500 years are 4% and 2.5% respectively. In less than 100 years there should be a considerable reduction in the Swedish CO 2 -C emissions even if only every second new logging residue-produced TWH replaces a fossil-fuel-produced TWh. From a long-term perspective, effects on carbon reservoirs in Sweden, caused by conversions to whole-tree harvesting in forestry and to willow production on redundant farmland, can be considered negligible in terms of their influence on the carbon dioxide budget of Sweden. The orders of magnitude of influencing fluxes is exemplified in the following: The annual production of 50 TWh, whereof 40 TWh from logging residues, 8 TWh from willow and 2 TWh from annual crops is estimated to cause a total net decrease of the carbon reservoirs within Sweden corresponding to 32 Tg CO 2 -C, whereas the annual production of 50 TWh from oil combustion should emit 1200 Tg CO 2 -C in 300 years, 2000 Tg CO 2 -C in 500 years and so on. (au). 17 refs., 4 tabs

  15. Integration of direct carbon and hydrogen fuel cells for highly efficient power generation from hydrocarbon fuels

    Energy Technology Data Exchange (ETDEWEB)

    Muradov, Nazim; Choi, Pyoungho; Smith, Franklyn; Bokerman, Gary [Florida Solar Energy Center, University of Central Florida, 1679 Clearlake Road, Cocoa, FL 32922-5703 (United States)

    2010-02-15

    In view of impending depletion of hydrocarbon fuel resources and their negative environmental impact, it is imperative to significantly increase the energy conversion efficiency of hydrocarbon-based power generation systems. The combination of a hydrocarbon decomposition reactor with a direct carbon and hydrogen fuel cells (FC) as a means for a significant increase in chemical-to-electrical energy conversion efficiency is discussed in this paper. The data on development and operation of a thermocatalytic hydrocarbon decomposition reactor and its coupling with a proton exchange membrane FC are presented. The analysis of the integrated power generating system including a hydrocarbon decomposition reactor, direct carbon and hydrogen FC using natural gas and propane as fuels is conducted. It was estimated that overall chemical-to-electrical energy conversion efficiency of the integrated system varied in the range of 49.4-82.5%, depending on the type of fuel and FC used, and CO{sub 2} emission per kW{sub el}h produced is less than half of that from conventional power generation sources. (author)

  16. Method to produce carbon-cladded nuclear fuel particles

    International Nuclear Information System (INIS)

    Sturge, D.W.; Meaden, G.W.

    1978-01-01

    In the method charges of micro-spherules of fuel element are designed to have two carbon layers, whereby a one aims to achieve a uniform granulation (standard measurement). Two drums are used for this purpose connected behind one another. The micro-spherules coated with the first layer (phenolformaldehyde resin coated graphite particles) leave the first drum and enter the second one. Following the coating with a second layer, the micro-spherules are introduced into a grain size separator. The spherules that are too small are directly recycled into the second drum and those ones that are too large are recycled into the first drum after removing the graphite layers. The method may also be applied to metal cladded particles to manufacture cermet fuels. (RW) [de

  17. Recent Advances in Carbon Nanotube-Based Enzymatic Fuel Cells

    Energy Technology Data Exchange (ETDEWEB)

    Cosnier, Serge, E-mail: serge.cosnier@ujf-grenoble.fr; Holzinger, Michael; Le Goff, Alan [Département de Chimie Moléculaire (DCM) UMR 5250, Université Grenoble Alpes, Grenoble (France); Département de Chimie Moléculaire (DCM) UMR 5250, CNRS, Grenoble (France)

    2014-10-24

    This review summarizes recent trends in the field of enzymatic fuel cells. Thanks to the high specificity of enzymes, biofuel cells can generate electrical energy by oxidation of a targeted fuel (sugars, alcohols, or hydrogen) at the anode and reduction of oxidants (O{sub 2}, H{sub 2}O{sub 2}) at the cathode in complex media. The combination of carbon nanotubes (CNT), enzymes and redox mediators was widely exploited to develop biofuel cells since the electrons involved in the bio-electrocatalytic processes can be efficiently transferred from or to an external circuit. Original approaches to construct electron transfer based CNT-bioelectrodes and impressive biofuel cell performances are reported as well as biomedical applications.

  18. Development of molten carbonate fuel cells for power generation

    Science.gov (United States)

    1980-04-01

    The broad and comprehensive program included elements of system definition, cell and system modeling, cell component development, cell testing in pure and contaminated environments, and the first stages of technology scale up. Single cells, with active areas of 45 sq cm and 582 sq cm, were operated at 650 C and improved to state of the art levels through the development of cell design concepts and improved electrolyte and electrode components. Performance was shown to degrade by the presence of fuel contaminants, such as sulfur and chlorine, and due to changes in electrode structure. Using conventional hot press fabrication techniques, electrolyte structures up to 20" x 20" were fabricated. Promising approaches were developed for nonhot pressed electrolyte structure fabrication and a promising electrolyte matrix material was identified. This program formed the basis for a long range effort to realize the benefits of molten carbonate fuel cell power plants.

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

    Science.gov (United States)

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

    2017-10-01

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

  20. The effect of reformer gas mixture on the performance and emissions of an HSDI diesel engine

    OpenAIRE

    Christodoulou, Fanos; Megaritis, Athanasios

    2014-01-01

    This article has been made available through the Brunel Open Access Publishing Fund. Exhaust gas assisted fuel reforming is an attractive on-board hydrogen production method, which can open new frontiers in diesel engines. Apart from hydrogen, and depending on the reactions promoted, the reformate typically contains a significant amount of carbon monoxide, which is produced as a by-product. Moreover, admission of reformed gas into the engine, through the inlet pipe, leads to an increase of...

  1. Carbon dioxide from fossil fuels. Adapting to uncertainty

    Energy Technology Data Exchange (ETDEWEB)

    Chen, K; Winter, R C; Bergman, M K

    1980-12-01

    The world is likely to experience noticeable carbon dioxide induced global warming by the beginning of the next century if high annual growth rates of fossil fuel energy use continue. This article proposes some ideas about what can be done from a policy-making perspective if the CO$SUB$2 effects occur, and how, in addition, we can deal now with the uncertainties. It also considers questions concerning the potential for control of CO$SUB$2 emissions drawing up on current work in long range coal-based energy technology assessment. (70 refs.)

  2. Carbonate fuel cell endurance: Hardware corrosion and electrolyte management status

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Farooque, M.; Maru, H.

    1993-01-01

    Endurance tests of carbonate fuel cell stacks (up to 10,000 hours) have shown that hardware corrosion and electrolyte losses can be reasonably controlled by proper material selection and cell design. Corrosion of stainless steel current collector hardware, nickel clad bipolar plate and aluminized wet seal show rates within acceptable limits. Electrolyte loss rate to current collector surface has been minimized by reducing exposed current collector surface area. Electrolyte evaporation loss appears tolerable. Electrolyte redistribution has been restrained by proper design of manifold seals.

  3. Carbonate fuel cell endurance: Hardware corrosion and electrolyte management status

    Energy Technology Data Exchange (ETDEWEB)

    Yuh, C.; Johnsen, R.; Farooque, M.; Maru, H.

    1993-05-01

    Endurance tests of carbonate fuel cell stacks (up to 10,000 hours) have shown that hardware corrosion and electrolyte losses can be reasonably controlled by proper material selection and cell design. Corrosion of stainless steel current collector hardware, nickel clad bipolar plate and aluminized wet seal show rates within acceptable limits. Electrolyte loss rate to current collector surface has been minimized by reducing exposed current collector surface area. Electrolyte evaporation loss appears tolerable. Electrolyte redistribution has been restrained by proper design of manifold seals.

  4. Fabrication of catalytic electrodes for molten carbonate fuel cells

    Science.gov (United States)

    Smith, James L.

    1988-01-01

    A porous layer of catalyst material suitable for use as an electrode in a molten carbonate fuel cell includes elongated pores substantially extending across the layer thickness. The catalyst layer is prepared by depositing particulate catalyst material into polymeric flocking on a substrate surface by a procedure such as tape casting. The loaded substrate is heated in a series of steps with rising temperatures to set the tape, thermally decompose the substrate with flocking and sinter bond the catalyst particles into a porous catalytic layer with elongated pores across its thickness. Employed as an electrode, the elongated pores provide distribution of reactant gas into contact with catalyst particles wetted by molten electrolyte.

  5. Sulfur-Tolerant Autothermal Reforming Catalysts for Aviation Fuel, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — As solid oxide fuel cells (SOFCs) approach commercialization, interest in broader applications of this technology is mounting. While the first commercialized systems...

  6. Development, investigation and modelling of a micro reformer as part of a system for off-grid power supply with PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Rochlitz, Lisbeth

    2008-11-18

    In this thesis a micro reformer fuel cell system ({mu}RFCS) for 300 Wel off-grid power supply, fuelled with bioethanol, was simulated, designed, developed and investigated in a test-rig. First a literature study was carried through to point out the specific characteristics of micro reforming, the most important being heat transfer, and present the systems currently under research and already on the market. As a next step, the processes of the RFCS were simulated with the commercial simulation tool CHEMCAD. This comprised thermodynamic equilibrium simulations for the separate reactions of steam reforming, water gas shift and selective methanation. It also included a simulation of the complete {mu}RFCS with thermodynamic equilibrium for all reactors and assumed values for heat loss and fuel cell efficiency. The resulting net electrical efficiency was 24%. As a third step, a reaction pathway scheme with parallel and serial reactions for the steam reforming reaction of ethanol was simulated, developed, evaluated and proven plausible by matching the simulation to experimental results obtained in the {mu}RFCS test rig. The equilibrium simulations were used to evaluate the catalyst screening carried through for reformer, water gas shift and selective methanation catalysts. The catalysts for the {mu}RFCS were chosen and the optimum operating conditions determined by the screening tests. Having accomplished the simulation and design of the system, the largest proportion of this work was spent on the construction, set-up, testing and evaluation of the complete {mu}RFCS. The focus for the evaluations lay on the reformer side of the system. The technical feasibility was demonstrated for an ethanol/water mix of 3 ml/min at S/C 3. The first tests without optimized heat and water management between the reformer system and the fuel cell system resulted in power output of around 115 W{sub el}, at a total electrical efficiency of 31%. (orig.)

  7. Pembuatan Fuel dari Liquid Hasil Pirolisis Plastik Polipropilen Melalui Proses Reforming Dengan Katalis NiO/γ-Al2O3

    Directory of Open Access Journals (Sweden)

    Mahendra Fajri Nugraha

    2013-09-01

    Full Text Available Estimasi jumlah timbulan sampah di Indonesia pada tahun 2008 mencapai 38,5 juta ton/tahun. Melihat dari sifat penyusun plastik yang tersusun dari komponen hidrokarbon minyak bumi, maka limbah plastik sangat berpotensi untuk dikonversi menjadi BBM. Tujuan penelitian ini Mempelajari proses konversi limbah plastik khususnya jenis polipropilen (PP menjadi fuel serta pengaruh berbagai macam komposisi katalis NiO/γ-Al2O3, temperatur, laju alir reaktan pada reactor reforming terhadap kualitas fuel (yield aromatis yang dihasilkan. Pada penelitian ini bahan baku yang digunakan merupakan plastik jenis Polipropilen (PP. Pada penelitian ini minyak yang telah dihasilkan pada proses pirolisis selanjutnya akan di reforming. Pada penelitian ini digunakan logam NiO dengan penyangga γ-Al2O3 (NiO/γ-Al2O3 sebagai katalis untuk proses reforming minyak hasil pirolisis plastik polipropilen. Variabel penelitian meliputi Loading Ni (% massa : 6; 10; 14, Laju alir (ml/jam : 2I7; 500; 690, Suhu reaksi (oC : 400; 450; 500. Berdasarkan hasil penelitian dan analisa diketahui bahwa % yield aromatis terbesar pada proses reforming minyak hasil pirolisis plastik polipropilen dihasilkan dengan kondisi operasi 14 % loading Ni pada katalis, temperatur reforming 500oC serta laju reaktan sebesar 217 mL/jam. Dengan kata lain dapat disimpulkan bahwa pada penelitian ini, hasil terbaik didapat pada variabel flowlaju terendah dan variabel suhu tertinggi. Kondisi operasi efektif dalam pembuatan fuel pada proses reforming diperoleh saat loading Ni pada katalis NiO/γ-Al2O3 14 %, temperatur reforming 400oC serta laju reaktan 500 mL/jam.

  8. Experimental evaluation of a Pt based heat exchanger methanol reformer for a HTPEM fuel cell

    DEFF Research Database (Denmark)

    Andreasen, Søren Juhl; Nielsen, Mads Pagh; Kær, Søren Knudsen

    2007-01-01

    The storage of hydrogen in hydrogen consuming applications is often inconvenient because of the very low density of hydrogen even at high pressures (0.014 kg/L @ 300 bar) or cryogenically (0.043 kg/L). Much higher volumetric energy densities can be achieved using liquid hydrocarbons as e.g. metha...... (up to 1-2%). This work examines the possibility of using a catalyst coated plate heat exchanger for the reforming process of methanol....

  9. Hybrid direct carbon fuel cells and their reaction mechanisms - a review

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2014-01-01

    with carbon capture and storage (CCS) due to the high purity of CO2 emitted in the exhaust gas. Direct carbon (or coal) fuel cells (DCFCs) are directly fed with solid carbon to the anode chamber. The fuel cell converts the carbon at the anode and the oxygen at the cathode into electricity, heat and reaction......As coal is expected to continue to dominate power generation demands worldwide, it is advisable to pursue the development of more efficient coal power generation technologies. Fuel cells show a much higher fuel utilization efficiency, emit fewer pollutants (NOx, SOx), and are more easily combined...

  10. Catalytic Reforming of Higher Hydrocarbon Fuels to Hydrogen: Process Investigations with Regard to Auxiliary Power Units

    OpenAIRE

    Kaltschmitt, Torsten

    2012-01-01

    This thesis discusses the investigation of the catalytic partial oxidation on rhodium-coated honeycomb catalysts with respect to the conversion of a model surrogate fuel and commercial diesel fuel into hydrogen for the use in auxiliary power units. Furthermore, the influence of simulated tail-gas recycling was investigated.

  11. Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends report is the authoritative reference for carbon dioxide (CO2) emissions,...

  12. CFD analysis of a solid oxide fuel cell with internal reforming: Coupled interactions of transport, heterogeneous catalysis and electrochemical processes

    Energy Technology Data Exchange (ETDEWEB)

    Janardhanan, Vinod M.; Deutschmann, Olaf [Institute for Chemical Technology and Polymer Chemistry, Engesserstr. 20, D-76131 Karlsruhe, University of Karlsruhe (TH) (Germany)

    2006-11-22

    Direct internal reforming in solid oxide fuel cell (SOFC) results in increased overall efficiency of the system. Present study focus on the chemical and electrochemical process in an internally reforming anode supported SOFC button cell running on humidified CH{sub 4} (3% H{sub 2} O). The computational approach employs a detailed multi-step model for heterogeneous chemistry in the anode, modified Butler-Volmer formalism for the electrochemistry and Dusty Gas Model (DGM) for the porous media transport. Two-dimensional elliptic model equations are solved for a button cell configuration. The electrochemical model assumes hydrogen as the only electrochemically active species. The predicted cell performances are compared with experimental reports. The results show that model predictions are in good agreement with experimental observation except the open circuit potentials. Furthermore, the steam content in the anode feed stream is found to have remarkable effect on the resulting overpotential losses and surface coverages of various species at the three-phase boundary. (author)

  13. Hydrogen production by dry reforming of methane with carbon dioxide in one-dimensional nickel-based catalysts

    International Nuclear Information System (INIS)

    Lopez U, A. C.

    2016-01-01

    The main objective of this thesis is development of nickel catalysts supported over 1D matrix of cerium oxide, to be used in dry reforming methane reaction with carbon dioxide for hydrogen production. The catalysts were characterized by: Temperature Programmed Reduction (TPR), Scanning Electronic Microscopy (Sem), Surface Area (Bet method) an X Ray Diffraction (XRD). The TPR technique allowed to define reduction temperature of the active phase in the catalyst, Sem technique showed that the CeO_2 matrix had a nano rod morphology. XRD allowed to identify the crystalline phases of the catalysts. Finally, the catalysts were tested in the dry reforming methane reaction, high catalytic activity and hydrogen production were performed at 700 degrees Celsius and the catalyst with 30 wt.% of nickel. (Author)

  14. LiquidPower-1. Development and proof-of-concept of core methanol reformer for stationary and motive fuel cell systems and hydrogen refuelling stations. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Krogsgaard, J.; Mortensen, Henrik [H2 Logic A/S, Herning (Denmark); Skipper, T. [Dantherm Power A/S, Hobro (Denmark)

    2013-03-15

    LiquidPower-1 has developed laboratory test systems for methanol reforming and tested reformers from four different suppliers. This has contributed to determining the state-of-the-art level for methanol reforming and enabled an update of the LiquidPower R and D Roadmap onwards a commercialisation of the technology. The project has achieved the following results: 1) A detailed technical specification of methanol reformers for the fuel cell back-up power and hydrogen refueling station markets has been conducted; 2) Laboratory test systems for methanol reformers has been developed and established at Dantherm Power and H2 Logic; 3) Initial test of reformers from four suppliers has been conducted - with two suppliers being selected for continued tests; 4) Extensive laboratory tests conducted of reformers from two suppliers, with the aim to determine state-of-the-art for price, efficiency, capacity and lifetime. Several errors and break-downs were experienced during the test period, which revealed a need for further R and D to improve lifetime and stability; 5) The LiquidPower F and U Roadmap has been updated. Reformer TCO targets (Total Cost of Operation) for each of the markets have been calculated including updated targets for efficiency and cost. These targets also serve as the main ones to be pursued as part of the continued R and D roadmap execution. Compared to the previous edition of the Roadmap, the project has confirmed the viability of methanol reforming, but also revealed that stability and lifetime needs to be addressed and solved before commencing commercialization of the technology. If the Roadmap is successful a commercialization can commence beyond 2015. (Author)

  15. Reforming fossil fuel prices in India: Dilemma of a developing economy

    International Nuclear Information System (INIS)

    Anand, Mukesh Kumar

    2016-01-01

    Over the period between 1990–1 and 2012–3, fossil fuel use on farms has risen and its indirect use in farming, particularly for non-energy purposes, is also growing. Consequently, both energy intensity and fossil fuel intensity are rising for Indian agriculture. But, these are declining for the aggregate Indian economy. Thus, revision of fossil fuel prices acquires greater significance for Indian agriculture than for rest of the economy. There are significant differences across crops. The crop-level analysis is supplemented by an alternative approach that utilizes a three-sector input–output (I–O) model for the Indian economy representing farming, fossil fuels, and rest of economy. Fossil fuels sector is assessed to portray, in general, strong forward linkages. The increase in total cost of farming, for a given change in fossil fuel prices, is estimated as a multiple of increase in direct input cost of fossil fuels in farming. From the three-sector aggregated economy this multiple was estimated at 3.99 for 1998–9. But it grew to 6.7 in 2007–8. The findings have stronger ramifications than commonly recognized, for inflation and cost of implementing the policy on food security. - Highlights: •Fossil fuels’ contribution in primary energy supply has risen from 55 to 75 per cent. •Energy intensity halved for aggregate GDP, but doubled for agricultural GDP. •Impact of fossil fuel price increase on farming costs mimics a widening spiral. •Total cost of farming may increase 6.7 times the increase in direct fuel input cost.

  16. Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments

    Science.gov (United States)

    Katherine C. Kelsey; Kallie L. Barnes; Michael G. Ryan; Jason C. Neff

    2014-01-01

    Forests store large amounts of carbon in forest biomass, and this carbon can be released to the atmosphere following forest disturbance or management. In the western US, forest fuel reduction treatments designed to reduce the risk of high severity wildfire can change forest carbon balance by removing carbon in the form of biomass, and by altering future potential...

  17. Carbon Tolerant Fuel Electrodes for Reversible Sofc Operating on Carbon Dioxide

    Directory of Open Access Journals (Sweden)

    Papazisi Kalliopi Maria

    2017-01-01

    Full Text Available A challenging barrier for the broad, successful implementation of Reversible Solid Oxide Fuel Cell (RSOFC technology for Mars application utilizing CO2 from the Martian atmosphere as primary reactant, remains the long term stability by the effective control and minimization of degradation resulting from carbon built up. The perovskitic type oxide material La0.75Sr0.25Cr0.9Fe0.1O3-δ (LSCF has been developed and studied for its performance and tolerance to carbon deposition, employed as bi-functional fuel electrode in a Reversible SOFC operating on the CO2 cycle (Solid Oxide Electrolysis Cell/SOEC: CO2 electrolysis, Solid Oxide Fuel Cell/SOFC: power generation through the electrochemical reaction of CO and oxygen. A commercial state-of-the-art NiO-YSZ (8% mol Y2O3 stabilized ZrO2 cermet was used as reference material. CO2 electrolysis and fuel cell operation in 70% CO/CO2 were studied in the temperature range of 900-1000°C. YSZ was used as electrolyte while LSM-YSZ/LSM (La0.2Sr0.8MnO3 as oxygen electrode. Results showed that LSCF had high and stable performance under RSOFC operation.

  18. Assessment of bio-fuel options for solid oxide fuel cell applications

    Science.gov (United States)

    Lin, Jiefeng

    diesel engine and truck idling with fuel cell auxiliary power unit system. The customized nozzle used for fuel vaporization and mixing achieved homogenous atomization of input hydrocarbon fuels (e.g., diesel, biodiesel, diesel-biodiesel blend, and biodiesel-ethanol-diesel), and improved the performance of fuel catalytic reformation. Given the same operating condition (reforming temperature, total oxygen content, water input flow, and gas hourly space velocity), the hydrocarbon reforming performance follows the trend of diesel > biodiesel-ethanol-diesel > diesel-biodiesel blend > biodiesel (i.e., diesel catalytic reformation has the highest hydrogen production, lowest risk of carbon formation, and least possibility of hot spot occurrence). These results provide important new insight into the use of bio-fuels and bio-fuel blends as a primary fuel source for solid oxide fuel cell applications.

  19. Catalytic Enhancement of Carbon Black and Coal-Fueled Hybrid Direct Carbon Fuel Cells

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Ippolito, Davide; Kammer Hansen, Kent

    2015-01-01

    , Ce1-xREExO2-δ (REE = Pr, Sm)) and metal oxides (LiMn2O4, Ag2O). Materials showing the highest activity in carbon black (Mn2O3, CeO2, Ce0.6Pr0.4O2-δ, Ag2O) were subsequently tested for catalytic activity toward bituminous coal, as revealed by both I-V-P curves and electrochemical impedance...... spectroscopy (EIS). Catalytic activity was evaluated as a function of various physical characteristics of doped ceria and manganese-based materials....

  20. Reforming processes for micro combined heat and powersystem based on solid oxide fuel cell

    DEFF Research Database (Denmark)

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

    2009-01-01

    Solid oxide fuel cell (SOFC) is a promising technology for decentralized power generation and cogeneration. This technology has several advantages: the high electric efficiency, which can be theoretically improved through integration in power cycles; the low emissions; and the possibility of using...... a large variety of gaseous fuels. The high operating temperature (700-1000°C) of SOFCs has a number of consequences, the most important of which are the possibility to partially reform the raw fuel in the fuel cell anode compartment and the possibility to use high quality heat for cogeneration....... In this work, different configurations of SOFC systems for decentralized electricity production are considered and studied. The balance of plant (BoP) components will be identified including fuel and air supply, fuel management, start-up steam, anode re-circulation, exhaust gas heat management, power...

  1. Carbon nanotube fiber mats for microbial fuel cell electrodes.

    Science.gov (United States)

    Delord, Brigitte; Neri, Wilfrid; Bertaux, Karen; Derre, Alain; Ly, Isabelle; Mano, Nicolas; Poulin, Philippe

    2017-11-01

    Novel carbon nanotube based electrodes of microbial fuel cells (MFC) have been developed. MFC is a promising technology for the wastewater treatment and the production of electrical energy from redox reactions of natural substrates. Performances of such bio-electrochemical systems depend critically on the structure and properties of the electrodes. The presently developed materials are made by weaving fibers solely comprised of carbon nanotubes. They exhibit a large scale porosity controlled by the weaving process. This porosity allows an easy colonization by electroactive bacteria. In addition, the fibers display a nanostructuration that promotes excellent growth and adhesion of the bacteria at the surface of the electrodes. This unique combination of large scale porosity and nanostructuration allows the present electrodes to perform better than carbon reference. When used as anode in a bioelectrochemical reactor in presence of Geobacter sulfurreducens bacteria, the present electrodes show a maximal current density of about 7.5mA/cm 2 . Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro-fluidic carrier

    Science.gov (United States)

    Scherrer, Barbara; Evans, Anna; Santis-Alvarez, Alejandro J.; Jiang, Bo; Martynczuk, Julia; Galinski, Henning; Nabavi, Majid; Prestat, Michel; Tölke, René; Bieberle-Hütter, Anja; Poulikakos, Dimos; Muralt, Paul; Niedermann, Philippe; Dommann, Alex; Maeder, Thomas; Heeb, Peter; Straessle, Valentin; Muller, Claude; Gauckler, Ludwig J.

    2014-07-01

    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer-micro-SOFC assembly. The device consists of a micro-reformer bonded to a silicon chip containing 30 micro-SOFC membranes and a functional glass carrier with gas channels and screen-printed heaters for start-up. Thermal independence of the device from the externally powered heater is achieved by exothermic reforming reactions above 470 °C. The reforming reaction and the fuel gas flow rate of the n-butane/air gas mixture controls the operation temperature and gas composition on the micro-SOFC membrane. In the temperature range between 505 °C and 570 °C, the gas composition after the micro-reformer consists of 12 vol.% to 28 vol.% H2. An open-circuit voltage of 1.0 V and maximum power density of 47 mW cm-2 at 565 °C is achieved with the on-chip produced hydrogen at the micro-SOFC membranes.

  3. Carbon-Based Nanomaterials in Biomass-Based Fuel-Fed Fuel Cells

    Directory of Open Access Journals (Sweden)

    Le Quynh Hoa

    2017-11-01

    Full Text Available Environmental and sustainable economical concerns are generating a growing interest in biofuels predominantly produced from biomass. It would be ideal if an energy conversion device could directly extract energy from a sustainable energy resource such as biomass. Unfortunately, up to now, such a direct conversion device produces insufficient power to meet the demand of practical applications. To realize the future of biofuel-fed fuel cells as a green energy conversion device, efforts have been devoted to the development of carbon-based nanomaterials with tunable electronic and surface characteristics to act as efficient metal-free electrocatalysts and/or as supporting matrix for metal-based electrocatalysts. We present here a mini review on the recent advances in carbon-based catalysts for each type of biofuel-fed/biofuel cells that directly/indirectly extract energy from biomass resources, and discuss the challenges and perspectives in this developing field.

  4. In-situ study of the gas-phase composition and temperature of an intermediate-temperature solid oxide fuel cell anode surface fed by reformate natural gas

    Science.gov (United States)

    Santoni, F.; Silva Mosqueda, D. M.; Pumiglia, D.; Viceconti, E.; Conti, B.; Boigues Muñoz, C.; Bosio, B.; Ulgiati, S.; McPhail, S. J.

    2017-12-01

    An innovative experimental setup is used for in-depth and in-operando characterization of solid oxide fuel cell anodic processes. This work focuses on the heterogeneous reactions taking place on a 121 cm2 anode-supported cell (ASC) running with a H2, CH4, CO2, CO and steam gas mixture as a fuel, using an operating temperature of 923 K. The results have been obtained by analyzing the gas composition and temperature profiles along the anode surface in different conditions: open circuit voltage (OCV) and under two different current densities, 165 mA cm-2 and 330 mA cm-2, corresponding to 27% and 54% of fuel utilization, respectively. The gas composition and temperature analysis results are consistent, allowing to monitor the evolution of the principal chemical and electrochemical reactions along the anode surface. A possible competition between CO2 and H2O in methane internal reforming is shown under OCV condition and low current density values, leading to two different types of methane reforming: Steam Reforming and Dry Reforming. Under a current load of 40 A, the dominance of exothermic reactions leads to a more marked increase of temperature in the portion of the cell close to the inlet revealing that current density is not uniform along the anode surface.

  5. Estimating diesel fuel consumption and carbon dioxide emissions from forest road construction

    Science.gov (United States)

    Dan Loeffler; Greg Jones; Nikolaus Vonessen; Sean Healey; Woodam Chung

    2009-01-01

    Forest access road construction is a necessary component of many on-the-ground forest vegetation treatment projects. However, the fuel energy requirements and associated carbon dioxide emissions from forest road construction are unknown. We present a method for estimating diesel fuel consumed and related carbon dioxide emissions from constructing forest roads using...

  6. Measuring the effect of fuel treatments on forest carbon using landscape risk analysis

    Science.gov (United States)

    A.A. Ager; M.A. Finney; A. McMahan; J. Carthcart

    2010-01-01

    Wildfire simulation modelling was used to examine whether fuel reduction treatments can potentially reduce future wildfire emissions and provide carbon benefits. In contrast to previous reports, the current study modelled landscape scale effects of fuel treatments on fire spread and intensity, and used a probabilistic framework to quantify wildfire effects on carbon...

  7. Extraction of Uranium Using Nitrogen Dioxide and Carbon Dioxide for Spent Fuel Reprocessing

    Energy Technology Data Exchange (ETDEWEB)

    Kayo Sawada; Daisuke Hirabayashi; Youichi Enokida [EcoTopia Science Institute, Nagoya University, Nagoya, 464-8603 (Japan)

    2008-07-01

    For the reprocessing of spent nuclear fuels, a new method to extract actinides from spent fuel using highly compressed gases, nitrogen dioxide and carbon dioxide was proposed. Uranium extraction from broken pieces, whose average grain size was 5 mm, of uranium dioxide pellet with nitrogen dioxide and carbon dioxide was demonstrated in the present study. (authors)

  8. Conversion of sewage sludge to clean solid fuel using hydrothermal carbonization: Hydrochar fuel characteristics and combustion behavior

    International Nuclear Information System (INIS)

    He, Chao; Giannis, Apostolos; Wang, Jing-Yuan

    2013-01-01

    Highlights: • The hydrothermal carbonization of sewage sludge process is developed. • Hydrochars are solid fuels with less nitrogen and sulfur contents. • The first order combustion reaction of hydrochars is derived. • Main combustion decomposition of hydrochars is easier and more stable. • Formation pathways of hydrochars during hydrothermal carbonization are proposed. - Abstract: Conventional thermochemical treatment of sewage sludge (SS) is energy-intensive due to its high moisture content. To overcome this drawback, the hydrothermal carbonization (HTC) process was used to convert SS into clean solid fuel without prior drying. Different carbonization times were applied in order to produce hydrochars possessing better fuel properties. After the carbonization process, fuel characteristics and combustion behaviors of hydrochars were evaluated. Elemental analysis showed that 88% of carbon was recovered while 60% of nitrogen and sulfur was removed. Due to dehydration and decarboxylation reactions, hydrogen/carbon and oxygen/carbon atomic ratios reduced to 1.53 and 0.39, respectively. It was found that the fuel ratio increased to 0.18 by prolonging the carbonization process. Besides, longer carbonization time seemed to decrease oxygen containing functional groups while carbon aromaticity structure increased, thereby rendering hydrochars highly hydrophobic. The thermogravimetric analysis showed that the combustion decomposition was altered from a single stage for raw sludge to two stages for hydrochars. The combustion reaction was best fitted to the first order for both raw sludge and hydrochars. The combustion of hydrochars is expected to be easier and more stable than raw sludge because of lower activation energy and pre-exponential factor

  9. Catalytic reforming of methane to syngas in an oxygen-permeative membrane reactor

    Energy Technology Data Exchange (ETDEWEB)

    Urano, Takeshi; Kubo, Keiko; Saito, Tomoyuki; Hitomi, Atsushi, E-mail: turano@jp.tdk.com [Materials and Process Development Center, TDK Corporation 570-2, Matsugashita, Minamihatori, Narita, Chiba 286-8588 (Japan)

    2011-05-15

    For fuel cell applications, partial oxidative reforming of methane to syngas, hydrogen and carbon monoxide, was performed via a dense oxygen-permeative ceramic membrane composed by both ionic and electronic conductive materials. The modification of Ni-based catalyst by noble metals was investigated to increase oxygen permeation flux and decrease carbon deposition during reforming reaction. The role of each component in catalyst was also discussed.

  10. Demonstration of direct internal reforming for MCFC power plants

    Energy Technology Data Exchange (ETDEWEB)

    Aasberg-Petersen, K.; Christensen, P.S.; Winther, S.K. [HALDOR TOPSOE A/S, Lynby (Denmark)] [and others

    1996-12-31

    The conversion of methane into hydrogen for an MCFC by steam reforming is accomplished either externally or internally in the stack. In the case of external reforming the plant electrical efficiency is 5% abs. lower mainly because more parasitic power is required for air compression for stack cooling. Furthermore, heat produced in the stack must be transferred to the external reformer to drive the endothermic steam reforming reaction giving a more complex plant lay-out. A more suitable and cost effective approach is to use internal steam reforming of methane. Internal reforming may be accomplished either by Indirect Internal Reforming (DIR) and Direct Internal Reforming (DIR) in series or by DIR-only as illustrated. To avoid carbon formation in the anode compartment higher hydrocarbons in the feedstock are converted into hydrogen, methane and carbon oxides by reaction with steam in ail adiabatic prereformer upstream the fuel cell stack. This paper discusses key elements of the desire of both types of internal reforming and presents data from pilot plants with a combined total of more than 10,000 operating hours. The project is being carried out as part of the activities of the European MCFC Consortium ARGE.

  11. The Seasonal and Spatial Distribution of Carbon Dioxide Emissions from Fossil Fuels in Asia

    Science.gov (United States)

    Gregg, J. S.; Andres, R. J.

    2006-12-01

    Carbon dioxide emissions from fossil-fuel consumption are presented for the five Asian countries that are among the global leaders in anthropogenic carbon emissions: China (13% of global total), Japan (5% of global total), India (5% of global total), South Korea (2% of global total), and Indonesia (1% of global total). Together, these five countries represent over a quarter of the world's fossil-fuel based carbon emissions. Moreover, these countries are rapidly developing and energy demand has grown dramatically in the last two decades. A method is developed to estimate the spatial and seasonal flux of fossil-fuel consumption, thereby greatly improving the temporal and spatial resolution of anthropogenic carbon dioxide emissions. Currently, only national annual data for anthropogenic carbon emissions are available, and as such, no understanding of seasonal or sub-national patterns of emissions are possible. This methodology employs fuel distribution data from representative sectors of the fossil-fuel market to determine the temporal and spatial patterns of fuel consumption. These patterns of fuel consumption are then converted to patterns of carbon emissions. The annual total emissions estimates produced by this method are consistent to those maintained by the United Nations. Improved estimates of temporal and spatial resolution of the human based carbon emissions allows for better projections about future energy demands, carbon emissions, and ultimately the global carbon cycle.

  12. Research and Development of a PEM Fuel Cell, Hydrogen Reformer, and Vehicle Refueling Facility

    Energy Technology Data Exchange (ETDEWEB)

    Edward F. Kiczek

    2007-08-31

    Air Products and Chemicals, Inc. has teamed with Plug Power, Inc. of Latham, NY, and the City of Las Vegas, NV, to develop, design, procure, install and operate an on-site hydrogen generation system, an alternative vehicle refueling system, and a stationary hydrogen fuel cell power plant, located in Las Vegas. The facility will become the benchmark for validating new natural gas-based hydrogen systems, PEM fuel cell power generation systems, and numerous new technologies for the safe and reliable delivery of hydrogen as a fuel to vehicles. Most important, this facility will serve as a demonstration of hydrogen as a safe and clean energy alternative. Las Vegas provides an excellent real-world performance and durability testing environment.

  13. Reformed Methanol Fuel Cell Systems - and their use in Electric Hybrid Systems

    DEFF Research Database (Denmark)

    Justesen, Kristian Kjær

    drive cycle, is then used in the context of the Outdoor Reliable Application using CLean Energy (ORACLE) project to predict the performance of a RMFC powered street sweeping machine before a prototype is made. After the prototype has been manufactured, the model is updated based on measurements...... that minimizes fluctuations in the output power of the RMFC system. When this is done, the fuel consumption drops to 46.85 [L], which is a reduction of 24.6%. It is further concluded that if the power consumption is minimized further it is realistic to reduce the RMFC power to 5 [kW] and the fuel consumption...... of an RMFC system is produced. This includes approximate models of the dynamics of the fuel cell and battery as well as the power consumption of the Balance Of Plant (BOP) consumers. The models are fitted on the basis of experiments and used to develop a PI controller with feedforward and anti-windup, which...

  14. Investigation of a methanol reformer concept considering the particular impact of dynamics and long-term stability for use in a fuel-cell-powered passenger car

    Science.gov (United States)

    Peters, R.; Düsterwald, H. G.; Höhlein, B.

    A methanol reformer concept including a reformer, a catalytic burner, a gas cleaning unit, a PEMFC and an electric motor for use in fuel-cell-powered passenger cars was investigated. Special emphasis was placed on the dynamics and the long-term stability of the reformer. Experiments on a laboratory scale were performed in a methanol steam reformer consisting of four different reactor tubes, which were separately balanced. Due to the endothermy of the steam reforming reaction of methanol, a sharp drop in the reaction temperature of about 50 K occurs at the beginning of the catalyst bed. This agrees well with the high catalytic activity at the entrance of the catalyst bed. Forty-five percent of the methanol was converted within the first 10 cm of the catalyst bed where 12.6 g of the CuO/ZnO catalyst was located. Furthermore, CO formation during methanol steam reforming strongly depends on methanol conversion. Long-term measurements for more than 700 h show that the active reaction zone moved through the catalyst bed. Calculations, on the basis of these experiments, revealed that 63 g of reforming catalyst was necessary for mobile PEMFC applications, in this case for 400 W el at a system efficiency of 42% and a theoretical specific hydrogen production of 5.2 m 3n/(h kg Cat). This amount of catalyst was assumed to maintain a hydrogen production of at least 80% of the original amount over an operating range of 3864 h. Cycled start-up and shut-down processes of the methanol steam reformer under nitrogen and hydrogen atmospheres did not harm the catalytic activity. The simulation of the breakdown of the heating system, in which a liquid water/methanol mixture was in close contact with the catalyst, did not reveal any deactivation of the catalytic activity.

  15. Operating method of molten carbonate type fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Tsuneo

    1988-12-06

    Molten carbonate type fuel cell involves a problem of oxidation of anode while the unit is stopped. Although there is a method proposed wherein an inactive gas is supplied to anode during the stoppage, the market-available inactive gas contains a slight amount of oxygen which makes it difficult to prevent the deterioration of the anode. In this invention, at the start and the stop other than the normal operation, a protective gas mixture of an inactive gas with a small amount of hydrogen is supplied to the anode. The inactive gas is a commercial type nitrogen, argon or helium; hydrogen is mixed in amount 0.5 - 2.0% of the inactive gas. By this method, oxygen in air which comes in from the gas-sealed portion of the cell is reduced by hydrogen in the protective gas and is discharged in the form of water. 2 figs.

  16. Carbon components in the phosphoric acid fuel cell-an overview

    International Nuclear Information System (INIS)

    Appleby, J.

    1983-01-01

    The single breakthrough that has made the phosphoric acid fuel cell a practical reality has been the use of carbon or graphite components for the repeat parts of the cell stack. While the thermodynamic stability of carbon is such that rapid corrosion would be expected at the cathode at fuel cell operating temperature, its kinetic stability is remarkable despite the absence of passivating layers analogous to those on, for example, the Group VA elements niobium and tantalum. This happy accident, combined with the adequate electronic conductivity of the carbon materials used, has provided the opportunity to reduce fuel cell cost to attractive levels. The development of these carbon compounds is reviewed

  17. Hybrid Direct Carbon Fuel Cell Performance with Anode Current Collector Material

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Kammer Hansen, Kent

    2015-01-01

    collectors were studied: Au, Ni, Ag, and Pt. It was shown that the performance of the direct carbon fuel cell (DCFC) is dependent on the current collector materials, Ni and Pt giving the best performance, due to their catalytic activity. Gold is suggested to be the best material as an inert current collector......The influence of the current collector on the performance of a hybrid direct carbon fuel cell (HDCFC), consisting of solid oxide fuel cell (SOFC) with a molten carbonate-carbon slurry in contact with the anode, has been investigated using current-voltage curves. Four different anode current...

  18. Gauging citizen support for a low carbon fuel standard

    International Nuclear Information System (INIS)

    Rhodes, Ekaterina; Axsen, Jonn; Jaccard, Mark

    2015-01-01

    Since 2007, several variations of a low carbon fuel standard (LCFS) have been implemented around the world. While emerging research tends to focus on greenhouse gas emission reductions from an LCFS, no studies have assessed the policy's political acceptability—a critical component of implementation. We elicit public support for an existing LCFS in British Columbia and a hypothetical (proposed) LCFS for the rest of Canada using survey data collected from a representative sample of Canadian citizens (n=1306). Specifically, we assess: (1) citizen awareness of British Columbia's LCFS, (2) stated citizen support for the LCFS, and (3) how individual characteristics relate to levels of citizen support. We find that British Columbia's LCFS is almost unknown among British Columbia respondents, but once explained, 90% of respondents support it. We refer to this combination of low knowledge and high support as “passive support.” We find similarly broad support in all other Canadian provinces, implying that citizen opposition is unlikely in jurisdictions considering an LCFS. Statistical analysis identifies some individual characteristics associated with LCFS support, including attitudes, demographics, and contextual factors. Results indicate where policymakers might anticipate opposition if it arises due to increased policy stringency or media coverage. - Highlights: • Most citizens are unaware of British Columbia's low carbon fuel standard (LCFS). • We observe passive support: low awareness and high support of the policy. • An LCFS achieves broad support among British Columbia's and Canadian citizens. • Households relying on single occupancy vehicles are less likely to support an LCFS

  19. Reforming of Liquid Hydrocarbons in a Novel Hydrogen-Selective Membrane-Based Fuel Processor

    Energy Technology Data Exchange (ETDEWEB)

    Shamsuddin Ilias

    2006-03-10

    In this work, asymmetric dense Pd/porous stainless steel composite membranes were fabricated by depositing palladium on the outer surface of the tubular support. The electroless plating method combined with an osmotic pressure field was used to deposit the palladium film. Surface morphology and microstructure of the composite membranes were characterized by SEM and EDX. The SEM and EDX analyses revealed strong adhesion of the plated pure palladium film on the substrate and dense coalescence of the Pd film. Membranes were further characterized by conducting permeability experiments with pure hydrogen, nitrogen, and helium gases at temperatures from 325 to 450 C and transmembrane pressure differences from 5 to 45 psi. The permeation results showed that the fabricated membranes have both high hydrogen permeability and selectivity. For example, the hydrogen permeability for a composite membrane with a 20 {micro}m Pd film was 3.02 x 10{sup -5} moles/m{sup 2}.s.Pa{sup 0.765} at 450 C. Hydrogen/nitrogen selectivity for this composite membrane was 1000 at 450 C with a transmembrane pressure difference of 14.7 psi. Steam reforming of methane is one of the most important chemical processes in hydrogen and syngas production. To investigate the usefulness of palladium-based composite membranes in membrane-reactor configuration for simultaneous production and separation of hydrogen, steam reforming of methane by equilibrium shift was studied. The steam reforming of methane using a packed-bed inert membrane tubular reactor (PBIMTR) was simulated. A two-dimensional pseudo-homogeneous reactor model with parallel flow configuration was developed for steam reforming of methane. The shell volume was taken as the feed and sweep gas was fed to the inside of the membrane tube. Radial diffusion was taken into account for concentration gradient in the radial direction due to hydrogen permeation through the membrane. With appropriate reaction rate expressions, a set of partial differential

  20. An Experiment on the Carbonization of Fuel Compact Matrix Graphite for HTGR

    International Nuclear Information System (INIS)

    Lee, Young Woo; Kim, Joo Hyoung; Cho, Moon Sung

    2012-01-01

    The fuel element for HTGR is manufactured by mixing coated fuel particles with matrix graphite powder and forming into either pebble type or cylindrical type compacts depending on their use in different HTGR cores. The coated fuel particle, the so-called TRISO particle, consists of 500-μm spherical UO 2 particles coated with the low density buffer Pyrolytic Carbon (PyC) layer, the inner and outer high density PyC layer and SiC layer sandwiched between the two inner and outer PyC layers. The coated TRISO particles are mixed with a properly prepared matrix graphite powder, pressed into a spherical shape or a cylindrical compact, and finally heat-treated at about 1800 .deg. C. These fuel elements can have different sizes and forms of compact. The basic steps for manufacturing a fuel element include preparation of graphite matrix powder, over coating the fuel particles, mixing the fuel particles with a matrix powder, carbonizing green compact, and the final high-temperature heat treatment of the carbonized fuel compact. The carbonization is a process step where the binder that is incorporated during the matrix graphite powder preparation step is evaporated and the residue of the binder is carbonized during the heat treatment at about 1073 K, In order to develop a fuel compact fabrication technology, and for fuel matrix graphite to meet the required material properties, it is of extreme importance to investigate the relationship among the process parameters of the matrix graphite powder preparation, fabrication parameters of fuel element green compact and the carbonization condition, which has a strong influence on further steps and the material properties of fuel element. In this work, the carbonization behavior of green compact samples prepared from the matrix graphite powder mixtures with different binder materials was investigated in order to elucidate the behavior of binders during the carbonization heat treatment by analyzing the change in weight, density and its

  1. The carbon curse: Are fuel rich countries doomed to high CO2 intensities?

    International Nuclear Information System (INIS)

    Friedrichs, Jörg; Inderwildi, Oliver R.

    2013-01-01

    The carbon curse is a new theory, related to but distinct from the resource curse. It states that fossil-fuel rich countries tend to follow more carbon-intensive developmental pathways than [if they were] fossil-fuel poor countries, due to a hitherto unappreciated syndrome of causal mechanisms. First, fuel rich countries emit significant amounts of CO 2 in the extraction of fuel and through associated wasteful practices such as gas flaring. Second, easy access to domestic fuel in such countries leads to crowding-out effects for their energy mix and economic structure (for example, abundant oil may displace other fuels from the energy mix and lead to the “Dutch Disease”). Third, fuel abundance weakens the economic incentive to invest in energy efficiency. Fourth, governments in fuel rich countries are under considerable pressure to grant uneconomic fuel consumption subsidies, which further augments the carbon intensity of their economic output. Due to the combined effect of these causal mechanisms, it is genuinely difficult for fuel rich countries to evade carbon-intensive developmental pathways. And yet there are remarkable exceptions like Norway. Such positive outliers indicate that the carbon curse is not destiny when appropriate policies are adopted. - Highlights: • Fuel rich countries appear doomed to high carbon intensity, for four reasons. • First, extractive emissions; and, second, fuel-related crowding-out effects. • Third, weaker incentives to invest in improvements of energy efficiency. • Fourth, significant pressure to grant uneconomic fuel consumption subsidies. • But the carbon curse is not destiny, as indicated by positive outliers like Norway

  2. Non-catalytic recuperative reformer

    Science.gov (United States)

    Khinkis, Mark J.; Kozlov, Aleksandr P.; Kurek, Harry

    2015-12-22

    A non-catalytic recuperative reformer has a flue gas flow path for conducting hot flue gas from a thermal process and a reforming mixture flow path for conducting a reforming mixture. At least a portion of the reforming mixture flow path is embedded in the flue gas flow path to permit heat transfer from the hot flue gas to the reforming mixture. The reforming mixture flow path contains substantially no material commonly used as a catalyst for reforming hydrocarbon fuel (e.g., nickel oxide, platinum group elements or rhenium), but instead the reforming mixture is reformed into a higher calorific fuel via reactions due to the heat transfer and residence time. In a preferred embodiment, extended surfaces of metal material such as stainless steel or metal alloy that are high in nickel content are included within at least a portion of the reforming mixture flow path.

  3. Direct synthesis of nitrogen-containing carbon nanotubes on carbon paper for fuel cell electrode

    Science.gov (United States)

    Yin, Wong Wai; Daud, Wan Ramli Wan; Mohamad, Abu Bakar; Kadhum, Abdul Amir Hassan; Majlan, Edy Herianto; Shyuan, Loh Kee

    2012-06-01

    Organic catalyst has recently been identified as the potential substitution for expensive platinum electrocatalyst for fuel cell application. Numerous studies have shown that the nitrogen-containing carbon nanotubes (N-CNT) can be synthesized through spray pyrolysis or floating chemical vapor deposition (CVD) technique using various type of organometallic as precursors. This paper presents the method of synthesis and the initial findings of the growth of N-CNT directly on carbon paper using a modified CVD technique. In this research, nickel (II) phthalocyanines (Ni-Pc) as precursor was dissolved in ethanol solvent, stirred and sonicated to become homogenized. The solution was poured into a bubbler and heated up to allow the mixture to vaporize. Subsequently, the solution vapor was flowed into the tubical reactor maintained at 900°C. Carbon paper sputtered with nickel nanoparticles was used as the substrate. The synthesized sample was examined through Field Emission Scanning Electron Microscopy (FESEM), Atomic Force Microscopy (AFM) and Fourier Transform Infra-Red (FTIR). Long, entangled and compartmentalized nanotubes with tube diameter ranging 23-27 nm were found covered the carbon paper surface with approximate of 5.5-6.0 μm in thickness. EDX analysis has successfully showed the presence of nitrogen in the carbon nanotube. FTIR analysis showed the presence of the C-N bond on CNT.

  4. Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments

    OpenAIRE

    Kelsey, Katharine C; Barnes, Kallie L; Ryan, Michael G; Neff, Jason C

    2014-01-01

    Background Forests store large amounts of carbon in forest biomass, and this carbon can be released to the atmosphere following forest disturbance or management. In the western US, forest fuel reduction treatments designed to reduce the risk of high severity wildfire can change forest carbon balance by removing carbon in the form of biomass, and by altering future potential wildfire behavior in the treated stand. Forest treatment carbon balance is further affected by the fate of this biomass ...

  5. Carbon-14 discharges from the nuclear fuel cycle: Pt. 1

    International Nuclear Information System (INIS)

    McCartney, M.; Baxter, M.S.; Scott, E.M.

    1988-01-01

    The radiological impact of 14 C produced by the nuclear fuel cycle is assessed using an advanced 25-box model of the carbon cycle coupled with a range of feasible energy-use scenarios. In particular, this study estimates both the short- and long-term dose implications to the global population. In the former context, it is predicted that the atmospheric 14 C specific activity in the year 2050 will be 234 Bq kg -1 (carbon), corresponding to delivery of an individual effective dose equivalent rate of 15 μSv year -1 . The contribution of reactor-derived 14 C to the individual dose rate increases steadily throughout this period, reaching 1.8 μSv year -1 in 2050, well within ICRP limits. In the longer term, however, the collective effective dose equivalent commitment is conservatively estimated at 141 man Sv TBq -1 , corresponding to 480 man Sv (GW(e) year) -1 . These figures indicate that 14 C could generate one of the largest contributions to the total dose to man from nuclear power production. (author)

  6. The role of various fuels on microwave-enhanced combustion synthesis of CuO/ZnO/Al2O3 nanocatalyst used in hydrogen production via methanol steam reforming

    International Nuclear Information System (INIS)

    Ajamein, Hossein; Haghighi, Mohammad; Alaei, Shervin

    2017-01-01

    Graphical abstract: CuO/ZnO/Al 2 O 3 nanocatalysts were synthesized by the fast and simple microwave enhanced combustion method. Considering that the fuel type is one of the effective parameters on quality of the prepared nanocatalysts, different fuels such as sorbitol, propylene glycol, glycerol, diethylene glycol and ethylene glycol were used. XRD, FESEM, FTIR, EDX, and BET analyses were applied to determine the physicochemical properties of fabricated nanocatalysts. The catalytic experiments were performed in a fixed bed reactor in the temperature range of 160–300 °C. The characteristic and reactivity properties of fabricated nanocatalysts proved that ethylene glycol is the suitable fuel for preparation of CuO/ZnO/Al 2 O 3 nanocatalysts via microwave enhanced combustion method. - Highlights: • Microwave combustion synthesis of CuO/ZnO/Al 2 O 3 nanocatalysts by different fuels. • Enhancement of methanol conversion at low temperatures by selecting proper fuel. • Providing a large number of combustion pores by application of ethylene glycol as fuel. • Increase of CO selectivity in steam methanol reforming by Zn(0 0 2) crystallite facet. - Abstract: A series of CuO/ZnO/Al 2 O 3 nanocatalysts were synthesized by the microwave enhanced combustion method to evaluate the influence of fuel type. Sorbitol, propylene glycol, glycerol, diethylene glycol and ethylene glycol were used as fuel. XRD results revealed that application of ethylene glycol led to highly dispersed CuO and ZnO crystals. It was more highlighted about Cu(1 1 1) crystallite facet which known as the main active site of methanol steam reforming. Moreover, using ethylene glycol resulted homogeneous morphology and narrow particles size distribution (average surface particle size is about 265 nm). Due to the significant physicochemical properties, the catalytic experiments showed that the sample prepared by ethylene glycol achieved total conversion of methanol at 260 °C. Its carbon monoxide

  7. The impact of steam and current density on carbon formation from biomass gasification tar on Ni/YSZ, and Ni/CGO solid oxide fuel cell anodes

    Science.gov (United States)

    Mermelstein, Joshua; Millan, Marcos; Brandon, Nigel

    The combination of solid oxide fuel cells (SOFCs) and biomass gasification has the potential to become an attractive technology for the production of clean renewable energy. However the impact of tars, formed during biomass gasification, on the performance and durability of SOFC anodes has not been well established experimentally. This paper reports an experimental study on the mitigation of carbon formation arising from the exposure of the commonly used Ni/YSZ (yttria stabilized zirconia) and Ni/CGO (gadolinium-doped ceria) SOFC anodes to biomass gasification tars. Carbon formation and cell degradation was reduced through means of steam reforming of the tar over the nickel anode, and partial oxidation of benzene model tar via the transport of oxygen ions to the anode while operating the fuel cell under load. Thermodynamic calculations suggest that a threshold current density of 365 mA cm -2 was required to suppress carbon formation in dry conditions, which was consistent with the results of experiments conducted in this study. The importance of both anode microstructure and composition towards carbon deposition was seen in the comparison of Ni/YSZ and Ni/CGO anodes exposed to the biomass gasification tar. Under steam concentrations greater than the thermodynamic threshold for carbon deposition, Ni/YSZ anodes still exhibited cell degradation, as shown by increased polarization resistances, and carbon formation was seen using SEM imaging. Ni/CGO anodes were found to be more resilient to carbon formation than Ni/YSZ anodes, and displayed increased performance after each subsequent exposure to tar, likely due to continued reforming of condensed tar on the anode.

  8. Trends and Issues in California's Low Carbon Fuel Standard - Learning from Response to Existing Climate Policy

    Science.gov (United States)

    Witcover, J.

    2015-12-01

    Debate over lower greenhouse gas (GHG) emissions from transportation has included heated discussion about appropriate policies and their cost and feasibility. One prominent policy mechanism, a carbon intensity standard, rates transport fuels based on analysis of lifecycle GHG emissions, and targets lower fuel pool carbon intensity through a market mechanism that uses a system of tradable, bankable credits and deficits. California instituted such a policy -- the Low Carbon Fuel Standard (LCFS) - in 2010, which targets a 10% carbon intensity (CI) reduction by 2020. The program rolled out amid concerns over slow development of new fuels expected to be very low carbon (such as cellulosic) and has faced court challenges that added considerable policy uncertainty. Since the program's start, state transport energy mix has shifted modestly but noticeably. Looking ahead, emerging issues for the program include amendments and re-adoption in response to a court ruling, potential interaction with California's multi-sector cap on carbon emissions (which started covering transport fuels in 2015), and impacts from similar CI standards in other jurisdictions. This study provides an analysis of fuel mix changes since the LCFS was implemented in 2011, and a discussion of emerging issues focusing on policy interaction. Descriptive statistics on alternative fuel use, available fuel pathways, and CI ratings are presented based on data from the California Air Resources Board (which runs the program). They document a shift towards more alternative fuels in a more diverse mix, with lower average CI ratings for most alternative fuel types. Financial incentives for various fuels are compared under the LCFS and the US federal Renewable Fuel Standard; disincentives from conceptually different carbon pricing schemes under the LCFS and the Cap-and-Trade are also outlined. The results provide important information on response to an existing market-based policy mechanism for addressing GHG

  9. Control loop design and control performance study on direct internal reforming solid oxide fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, H.; Weng, S.; Su, M. [Key Laboratory of Power Machinery and Engineering of the Education Ministry, Shanghai Jiao Tong University, Shanghai 200240 (China)

    2009-10-15

    A solid oxide fuel cell (SOFC) stack is a complicated nonlinear power system. Its system model includes a set of partial differential equations that describe species, mass, momentum and energy conservation, as well as the electrochemical reaction models. The validation and verification of the control system by experiment is very expensive and difficult. Based on the distributed and lumped model of a one-dimensional SOFC, the dynamic performance with different control loops for SOFC is investigated. The simulation result proves that the control system is appropriate and feasible, and can effectively satisfy the requirement of variable load power demand. This simulation model not only can prevent some latent dangers of the fuel cell system but also predict the distributed parameters' characteristics inside the SOFC system. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  10. Analysis of refabricated fuel: determination of carbon in uranium plutonium mixed carbide

    International Nuclear Information System (INIS)

    Huwyler, S.

    1977-09-01

    In developing uranium plutonium mixed carbide which represents an advanced fuel for breeder reactors carbon analysis is an important means of determining the stoichiometry. Methods of carbon determination are briefly reviewed. The carbon determination using a LECO WR-12 Carbon Determinator is treated in detail and experience of three years operation communicated. Problems arising from operating the LECO-apparatus in a glove box are discussed. It is pointed out that carbon determination with the LECO-apparatus is a very fast method with good precision and well suited for the routine analysis of mixed carbide fuel. The accuracy of the method is checked by means of a standard. (Auth.)

  11. Nickel-based anode with water storage capability to mitigate carbon deposition for direct ethanol solid oxide fuel cells.

    Science.gov (United States)

    Wang, Wei; Su, Chao; Ran, Ran; Zhao, Bote; Shao, Zongping; Tade, Moses O; Liu, Shaomin

    2014-06-01

    The potential to use ethanol as a fuel places solid oxide fuel cells (SOFCs) as a sustainable technology for clean energy delivery because of the renewable features of ethanol versus hydrogen. In this work, we developed a new class of anode catalyst exemplified by Ni+BaZr0.4Ce0.4Y0.2O3 (Ni+BZCY) with a water storage capability to overcome the persistent problem of carbon deposition. Ni+BZCY performed very well in catalytic efficiency, water storage capability and coking resistance tests. A stable and high power output was well maintained with a peak power density of 750 mW cm(-2) at 750 °C. The SOFC with the new robust anode performed for seven days without any sign of performance decay, whereas SOFCs with conventional anodes failed in less than 2 h because of significant carbon deposition. Our findings indicate the potential applications of these water storage cermets as catalysts in hydrocarbon reforming and as anodes for SOFCs that operate directly on hydrocarbons. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. A review of catalysts for the electroreduction of carbon dioxide to produce low-carbon fuels.

    Science.gov (United States)

    Qiao, Jinli; Liu, Yuyu; Hong, Feng; Zhang, Jiujun

    2014-01-21

    This paper reviews recent progress made in identifying electrocatalysts for carbon dioxide (CO2) reduction to produce low-carbon fuels, including CO, HCOOH/HCOO(-), CH2O, CH4, H2C2O4/HC2O4(-), C2H4, CH3OH, CH3CH2OH and others. The electrocatalysts are classified into several categories, including metals, metal alloys, metal oxides, metal complexes, polymers/clusters, enzymes and organic molecules. The catalyts' activity, product selectivity, Faradaic efficiency, catalytic stability and reduction mechanisms during CO2 electroreduction have received detailed treatment. In particular, we review the effects of electrode potential, solution-electrolyte type and composition, temperature, pressure, and other conditions on these catalyst properties. The challenges in achieving highly active and stable CO2 reduction electrocatalysts are analyzed, and several research directions for practical applications are proposed, with the aim of mitigating performance degradation, overcoming additional challenges, and facilitating research and development in this area.

  13. Forest wildfire, fuel reduction treatments, and landscape carbon stocks: a sensitivity analysis

    Science.gov (United States)

    John L. Campbell; Alan A. Ager

    2013-01-01

    Fuel reduction treatments prescribed in fire-suppressed forests of western North America pose an apparent paradox with respect to terrestrial carbon management. Such treatments have the immediate effect of reducing forest carbon stocks but likely reduce future carbon losses through the combustion and mortality caused by high-severity wildfires. Assessing the long-term...

  14. Integral reactor system and method for fuel cells

    Science.gov (United States)

    Fernandes, Neil Edward; Brown, Michael S; Cheekatamarla, Praveen; Deng, Thomas; Dimitrakopoulos, James; Litka, Anthony F

    2013-11-19

    A reactor system is integrated internally within an anode-side cavity of a fuel cell. The reactor system is configured to convert hydrocarbons to smaller species while mitigating the lower production of solid carbon. The reactor system may incorporate one or more of a pre-reforming section, an anode exhaust gas recirculation device, and a reforming section.

  15. Measuring the effect of fuel treatments on forest carbon using landscape risk analysis

    Directory of Open Access Journals (Sweden)

    A. A. Ager

    2010-12-01

    Full Text Available Wildfire simulation modelling was used to examine whether fuel reduction treatments can potentially reduce future wildfire emissions and provide carbon benefits. In contrast to previous reports, the current study modelled landscape scale effects of fuel treatments on fire spread and intensity, and used a probabilistic framework to quantify wildfire effects on carbon pools to account for stochastic wildfire occurrence. The study area was a 68 474 ha watershed located on the Fremont-Winema National Forest in southeastern Oregon, USA. Fuel reduction treatments were simulated on 10% of the watershed (19% of federal forestland. We simulated 30 000 wildfires with random ignition locations under both treated and untreated landscapes to estimate the change in burn probability by flame length class resulting from the treatments. Carbon loss functions were then calculated with the Forest Vegetation Simulator for each stand in the study area to quantify change in carbon as a function of flame length. We then calculated the expected change in carbon from a random ignition and wildfire as the sum of the product of the carbon loss and the burn probabilities by flame length class. The expected carbon difference between the non-treatment and treatment scenarios was then calculated to quantify the effect of fuel treatments. Overall, the results show that the carbon loss from implementing fuel reduction treatments exceeded the expected carbon benefit associated with lowered burn probabilities and reduced fire severity on the treated landscape. Thus, fuel management activities resulted in an expected net loss of carbon immediately after treatment. However, the findings represent a point in time estimate (wildfire immediately after treatments, and a temporal analysis with a probabilistic framework used here is needed to model carbon dynamics over the life cycle of the fuel treatments. Of particular importance is the long-term balance between emissions from the

  16. Measuring the effect of fuel treatments on forest carbon using landscape risk analysis

    Science.gov (United States)

    Ager, A. A.; Finney, M. A.; McMahan, A.; Cathcart, J.

    2010-12-01

    Wildfire simulation modelling was used to examine whether fuel reduction treatments can potentially reduce future wildfire emissions and provide carbon benefits. In contrast to previous reports, the current study modelled landscape scale effects of fuel treatments on fire spread and intensity, and used a probabilistic framework to quantify wildfire effects on carbon pools to account for stochastic wildfire occurrence. The study area was a 68 474 ha watershed located on the Fremont-Winema National Forest in southeastern Oregon, USA. Fuel reduction treatments were simulated on 10% of the watershed (19% of federal forestland). We simulated 30 000 wildfires with random ignition locations under both treated and untreated landscapes to estimate the change in burn probability by flame length class resulting from the treatments. Carbon loss functions were then calculated with the Forest Vegetation Simulator for each stand in the study area to quantify change in carbon as a function of flame length. We then calculated the expected change in carbon from a random ignition and wildfire as the sum of the product of the carbon loss and the burn probabilities by flame length class. The expected carbon difference between the non-treatment and treatment scenarios was then calculated to quantify the effect of fuel treatments. Overall, the results show that the carbon loss from implementing fuel reduction treatments exceeded the expected carbon benefit associated with lowered burn probabilities and reduced fire severity on the treated landscape. Thus, fuel management activities resulted in an expected net loss of carbon immediately after treatment. However, the findings represent a point in time estimate (wildfire immediately after treatments), and a temporal analysis with a probabilistic framework used here is needed to model carbon dynamics over the life cycle of the fuel treatments. Of particular importance is the long-term balance between emissions from the decay of dead trees

  17. Hydrogen-based power generation from bioethanol steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Tasnadi-Asztalos, Zs., E-mail: tazsolt@chem.ubbcluj.ro; Cormos, C. C., E-mail: cormos@chem.ubbcluj.ro; Agachi, P. S. [Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, 11 Arany Janos, Postal code: 400028, Cluj-Napoca (Romania)

    2015-12-23

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

  18. Hydrogen-based power generation from bioethanol steam reforming

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  19. Hydrogen-based power generation from bioethanol steam reforming

    Science.gov (United States)

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

    2015-12-01

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

  20. Effect of Feed Composition Changing at Naphtha Catalytic Reforming Unit Due to Involvement of Gasoline Fraction Obtained by Diesel Fuels Hydrodewaxing into the Processing

    OpenAIRE

    Belinskaya, Natalia Sergeevna; Ivanchina, Emilia Dmitrievna; Ivashkina, Elena Nikolaevna; Frantsina, Evgeniya Vladimirovna; Silko, Galina Yurievna

    2014-01-01

    One of the primary products of hydrodewaxing process is stable gasoline, which is characterized by low octane number on the one hand. On the other hand, it contains a significant amount of iso-paraffins (on average 45% wt.) and naphthenes (on average 25% wt.), which are reagents in the naphtha catalytic reforming process primary reactions. Feasibility of stable gasoline obtained by means of diesel fuel catalytic hydrodewaxing process involving into the processing at the naphtha catalytic refo...

  1. Solid oxide fuel cell performance comparison fueled by methane, MeOH, EtOH and gasoline surrogate C_8H_1_8

    International Nuclear Information System (INIS)

    Liso, Vincenzo; Cinti, Giovanni; Nielsen, Mads P.; Desideri, Umberto

    2016-01-01

    Carbon deposition is a major cause of degradation in solid oxide fuel cell systems. The ability to predict carbon formation in reforming processes is thus absolutely necessary for stable operation of solid oxide fuel cell systems. In the open literature it is found that the steam input is always considered in large excess compared to what required by the reforming process with the purpose of reducing carbon formation and avoiding rapid degradation of the cell performance. This makes it difficult to consistently compare system performance with different fuels. In this work, the molar compositions at equilibrium are calculated for a minimum steam to carbon ratio for each fuel type. We carry out a thermodynamic analysis of fuel/steam system using Gibbs Free Energy minimization method. A mathematical relationship between Lagrange's multipliers and carbon activity in the gas phase was deduced. Minimum steam required for the reforming process for each fuel was related to the heat required for the reforming process and fuel cell open circuit voltage. Furthermore, in an experimental test, steam reforming product compositions were used to evaluate and compare SOFC performance with different hydrocarbons. Comparing the model to the experimental activity, it is revealed that at temperatures exceeding 800 °C the gas composition is dominated by hydrogen and carbon monoxide for any of the fuels considered leading to similar cell polarization curves performance for different fuels. The main effect on the performance is related to OCV values which are dependent on different steam content for each fuel. It was concluded that the magnitude of the heat requested for the fuel reforming process is the major difference in system performance when comparing different fuels. However, reforming kinetic effects can become predominant rather than thermodynamics, especially at lower temperatures.

  2. Selective catalytic oxidation: a new catalytic approach to the desulfurization of natural gas and liquid petroleum gas for fuel cell reformer applications

    Science.gov (United States)

    Lampert, J.

    In both natural gas and liquid petroleum gas (LPG), sulfur degrades the performance of the catalysts used in fuel reformers and fuel cells. In order to improve system performance, the sulfur must be removed to concentrations of less than 200 ppbv (in many applications to less than 20 ppbv) before the fuel reforming operation. Engelhard Corporation presents a unique approach to the desulfurization of natural gas and LPG. This new method catalytically converts the organic and inorganic sulfur species to sulfur oxides. The sulfur oxides are then adsorbed on a high capacity adsorbent. The sulfur compounds in the fuel are converted to sulfur oxides by combining the fuel with a small amount of air. The mixture is then heated from 250 to 270 °C, and contacted with a monolith supported sulfur tolerant catalyst at atmospheric pressure. When Engelhard Corporation demonstrated this catalytic approach in the laboratory, the result showed sulfur breakthrough to be less than 10 ppbv in the case of natural gas, and less than 150 ppbv for LPG. We used a simulated natural gas and LPG mixture, doped with a 50-170 ppmv sulfur compound containing equal concentrations of COS, ethylmercaptan, dimethylsulfide, methylethylsulfide and tetrahydrothiophene. There is no need for recycled H 2 as in the case for hydrodesulfurization.

  3. FUEL/CARBON PRICE VS. ABATEMENT TECHNOLOGY IN FREIGHT TRANSPORT

    Directory of Open Access Journals (Sweden)

    Eugen Ferdinand Spangenberg

    2017-12-01

    Full Text Available The current situation is the exponential increase in greenhouse gases (GHG, which is mainly caused by industrial and transport activities. The recent Paris agreement in 2015 (Framework Convention on Climate Change COP21, UNFCCC made it clear to everyone that CO2 emissions are to be limited in all areas of life. Alternative fuels with a lower environmental impact than carbon (CO2 emissions are hard to find if the overall footprint is to be taken into account. Nevertheless, there are some fuels that have less impact on climate change. One the other hand, the production of biofuels is a controversial matter, although it is a viable alternative to emissions reduction. CNG or LNG-powered vehicles are also better in terms of environmental pollution, but are hardly better with regard to CO2 impact when a Life Cycle Assessment (LCA is carried out. LNG (liquid natural gas, for example, is the future fuel in the maritime sector because of the stricter environmental regulations (SOx,NOx in the shipping industry. The battery-powered vehicle is another example of an environmentally friendly solution. The afore-mentioned measures can be considered as “abatement“ necessary in order to limit CO2 impact. The study shows that there are significant differences in the environmental impact between transport systems and the corresponding drive-system or associated energy base. The polluter should pay, which is a common basic principle in economic research. The Emission Trading Scheme (ETS has been introduced in order to ensure a reduction in CO2 output – emissions come with a price tag. An overall view is necessary, both en-vironmental and economic impact must be reconciled (cf. Spangenberg - TQI. The future viability of the transport system as we know it may change significantly over time if new environmental requirements or e.g. CO2 taxes or ETS are introduced in the freight sector. The abatement of CO2 should be effected primarily through technological

  4. Experimental determination of effective surface area and conductivities in the porous anode of molten carbonate fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, M.; Boden, A.; Sparr, M.; Lindbergh, G. [Central Research Institute for Electric Power Industry, Kanagawa (Japan)

    2006-07-14

    Stationary polarization curves and electrochemical impedance spectroscopy of a porous nickel anode in a molten carbonate fuel cell were obtained in order to determine the active surface area and conductivities with varying degree of electrolyte filling for two anode feed-gas compositions, one simulating operation with steam reformed natural gas and the other one gasified coal. The active surface area for coal gas is reduced by around 70-80% compared to the standard gas composition in the case of Li/Na carbonate. Moreover, an optimal degree of electrolyte filling was shifted toward higher filling degree in the case of operation with coal gas. In order to evaluate the experimental data a one-dimensional model was used. The reaction rate at the matrix/electrode interface is about five times higher than the average reaction rate in the whole electrode in case of 10% electrolyte filling. This result suggests that the lower limit of the filling degree of the anode should be around 15% in order to avoid non-uniform distribution of the reaction in the electrode. Therefore, in the case of applying Li/Na carbonate in the MCFC, an electrolyte distribution model taking into account the wetting properties of the electrode is required in order to set an optimal electrolyte filling degree in the electrode.

  5. Mechanism of carbon deposit - removal in methane dry reforming on supported metal catalysts

    NARCIS (Netherlands)

    Nagaoka, K.; Nagaoka, K.; Seshan, Kulathuiyer; Lercher, J.A.; Aika, A.; Iglesia, E.; Spivey, J.J.; Fleisc, T.H.

    2001-01-01

    The greater resistance to coke deposition for Pt/ZrO2 compared to Pt/Al2O3 in the CH4/CO2 reaction has been attributed to the higher reactivity of coke with CO2 on Pt/ZrO2 [1]. Hence, in this communication, the reaction of coke derived from methane (CHx: which is an intermediated in the reforming

  6. A review of low carbon fuel policies: Principles, program status and future directions

    International Nuclear Information System (INIS)

    Yeh, Sonia; Witcover, Julie; Lade, Gabriel E.; Sperling, Daniel

    2016-01-01

    A low carbon fuel standard (LCFS) is a market-based policy that specifies declining standards for the average lifecycle fuel carbon intensity (AFCI) of transportation fuels sold in a region. This paper: (i) compares transportation fuel carbon policies in terms of their economic efficiency, fuel price impacts, greenhouse gas emission reductions, and incentives for innovation; (ii) discusses key regulatory design features of LCFS policies; and (iii) provides an update on the implementation status of LCFS policies in California, the European Union, British Columbia, and Oregon. The economics literature finds that an intensity standard implicitly taxes emissions and subsidizes output. The output subsidy results in an intensity standard being inferior to a carbon tax in a first-best world, although the inefficiency can be corrected with a properly designed consumption tax (or mitigated by a properly designed carbon tax or cap-and-trade program). In California, from 2011 to 2015 the share of alternative fuels in the regulated transportation fuels pool increased by 30%, and the reported AFCI of all alternative fuels declined 21%. LCFS credit prices have varied considerably, rising to above $100/credit in the first half of 2016. LCFS programs in other jurisdictions share many features with California's, but have distinct provisions as well. - Highlights: • LCFS is a market-based policy that sets standards for carbon intensity of fuels. • We compare efficiency, price impacts, GHG emissions, and innovation of C policies. • In California, reported carbon intensity of alternative fuels declined 21% 2011–2015. • LCFS credit prices have varied considerably, rising to above $100/credit in the first half of 2016. • Other LCFS programs share many features with CA's and have distinct provisions.

  7. Carbon nanotubes based methanol sensor for fuel cells application.

    Science.gov (United States)

    Kim, D W; Lee, J S; Lee, G S; Overzet, L; Kozlov, M; Aliev, A E; Park, Y W; Yang, D J

    2006-11-01

    An electrochemical sensor is built using vertically grown multi-walled carbon nanotubes (MWNTs) micro-array to detect methanol concentration in water. This study is done for the potential use of the array as methanol sensor for portable units of direct methanol fuel cells (DMFCs). Platinum (Pt) nanoparticles electro-deposited CNTs (Pt/CNTs) electrode shows high sensitivity in the measurement of methanol concentration in water with cyclic voltammetry (CV) measurement at room temperature. Further investigation has also been undertaken to measure the concentration by changing the amount of the mixture of methanol and formic acid in water. We compared the performance of our micro array sensor built with Pt/CNTs electrodes versus that of Pt wire electrode using CV measurement. We found that our Pt/CNTs array sensor shows high sensitivity and detects methanol concentrations in the range of 0.04 M to 0.10 M. In addition, we found that co-use of formic acid as electrolyte enables us to measure up to 1.0 M methanol concentration.

  8. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes II. Steam:carbon ratio and current density

    Science.gov (United States)

    Kuhn, J.; Kesler, O.

    2015-03-01

    For the second part of a two part publication, coking thresholds with respect to molar steam:carbon ratio (SC) and current density in nickel-based solid oxide fuel cells were determined. Anode-supported button cell samples were exposed to 2-component and 5-component gas mixtures with 1 ≤ SC ≤ 2 and zero fuel utilization for 10 h, followed by measurement of the resulting carbon mass. The effect of current density was explored by measuring carbon mass under conditions known to be prone to coking while increasing the current density until the cell was carbon-free. The SC coking thresholds were measured to be ∼1.04 and ∼1.18 at 600 and 700 °C, respectively. Current density experiments validated the thresholds measured with respect to fuel utilization and steam:carbon ratio. Coking thresholds at 600 °C could be predicted with thermodynamic equilibrium calculations when the Gibbs free energy of carbon was appropriately modified. Here, the Gibbs free energy of carbon on nickel-based anode support cermets was measured to be -6.91 ± 0.08 kJ mol-1. The results of this two part publication show that thermodynamic equilibrium calculations with appropriate modification to the Gibbs free energy of solid-phase carbon can be used to predict coking thresholds on nickel-based anodes at 600-700 °C.

  9. Carbon nanotube-coated macroporous sponge for microbial fuel cell electrodes

    KAUST Repository

    Xie, Xing; Ye, Meng; Hu, Liangbing; Liu, Nian; McDonough, James R.; Chen, Wei; Alshareef, Husam N.; Criddle, Craig S.; Cui, Yi

    2012-01-01

    The materials that are used to make electrodes and their internal structures significantly affect microbial fuel cell (MFC) performance. In this study, we describe a carbon nanotube (CNT)-sponge composite prepared by coating a sponge with CNTs

  10. Carbon dioxide emissions from fossil fuel use: Recent performance and future prospects

    Energy Technology Data Exchange (ETDEWEB)

    Jefferson, Michael

    1998-12-01

    This publication gives an overview and discusses carbon dioxide emissions from fossil fuel use worldwide. Main themes discussed in this connection cover recent performance and future prospects. Some proposals on the reduction of CO{sub 2} emissions are given

  11. Thermal conductivity and stability of nano size carbon black filled PDMS: Fuel cell perspective

    CSIR Research Space (South Africa)

    Chen, H

    2011-01-01

    Full Text Available Carbon black filled Polydimethylsiloxane (PDMS) was considered as a prospective bipolar plate material candidate for a Fuel Cell. In this perspective, thermal conductivity and stability of the composites were investigated. Samples with filler weight...

  12. Development and Demonstration of Carbon Fuel Cell Final Report CRADA No. TC02091.0

    Energy Technology Data Exchange (ETDEWEB)

    Cooper, J. F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Berner, J. K. [Contained Energy, Inc., Shaker Heights, OH (United States)

    2017-09-08

    This was a collaborative effort between The Regents of the University of California, Lawrence Livermore National Laboratory (LLNL) and Contained Energy, Inc. (CEI), to conduct necessary research and to develop, fabricate and test a multi-cell carbon fuel cell.

  13. Highly stable and active Ni-doped ordered mesoporous carbon catalyst on the steam reforming of ethanol application

    Directory of Open Access Journals (Sweden)

    Josh Y.Z. Chiou

    2017-02-01

    Full Text Available A novel one-step direct synthesis of nickel embedded in an ordered mesoporous carbon catalyst (NiOMC is done in a basic medium of nonaqueous solution by a solvent evaporation-induced self-assembly process. The NiOMC sample is characterized by a variety of analytical and spectroscopy techniques, e.g., N2 adsorption/desorption isotherm measurement, X-ray diffraction (XRD, transmission electron microscopy (TEM and temperature-programed reduction (TPR. In this study, the NiOMC catalyst is found to exhibit superior catalytic activity for the steam reforming of ethanol (SRE, showing high hydrogen selectivity and durability. Ethanol can be completely converted at 350 °C over the NiOMC catalyst. Also, the durability of the NiOMC catalyst on the SRE reaction exceeds 100 h at 450 °C, with SH2 approaching 65% and SCO of less than 1%.

  14. METHANE DRY REFORMING OVER Ni SUPPORTED ON PINE SAWDUST ACTIVATED CARBON: EFFECTS OF SUPPORT SURFACE PROPERTIES AND METAL LOADING

    Directory of Open Access Journals (Sweden)

    Rafael García

    2015-05-01

    Full Text Available The influence of metal loading and support surface functional groups (SFG on methane dry reforming (MDR over Ni catalysts supported on pine-sawdust derived activated carbon were studied. Using pine sawdust as the catalyst support precursor, the smallest variety and lowest concentration of SFG led to best Ni dispersion and highest catalytic activity, which increased with Ni loading up to 3 Ni atoms nm-2. At higher Ni loading, the formation of large metal aggregates was observed, consistent with a lower "apparen" surface area and a decrease in catalytic activity. The H2/CO ratio rose with increasing reaction temperature, indicating that increasingly important side reactions were taking place in addition to MDR.

  15. Highly Dispersed Nickel-Containing Mesoporous Silica with Superior Stability in Carbon Dioxide Reforming of Methane: The Effect of Anchoring

    Directory of Open Access Journals (Sweden)

    Wenjia Cai

    2014-03-01

    Full Text Available A series of nickel-containing mesoporous silica samples (Ni-SiO2 with different nickel content (3.1%–13.2% were synthesized by the evaporation-induced self-assembly method. Their catalytic activity was tested in carbon dioxide reforming of methane. The characterization results revealed that the catalysts, e.g., 6.7%Ni-SiO2, with highly dispersed small nickel particles, exhibited excellent catalytic activity and long-term stability. The metallic nickel particle size was significantly affected by the metal anchoring effect between metallic nickel particles and unreduced nickel ions in the silica matrix. A strong anchoring effect was suggested to account for the remaining of small Ni particle size and the improved catalytic performance.

  16. Ni-SiO2 Catalysts for the Carbon Dioxide Reforming of Methane: Varying Support Properties by Flame Spray Pyrolysis

    Directory of Open Access Journals (Sweden)

    Emma C. Lovell

    2015-03-01

    Full Text Available Silica particles were prepared by flame spray pyrolysis (FSP as a support for nickel catalysts. The impact of precursor feed rate (3, 5 and 7 mL/min during FSP on the silica characteristics and the ensuing effect on catalytic performance for the carbon dioxide, or dry, reforming of methane (DRM was probed. Increasing the precursor feed rate: (i progressively lowered the silica surface area from ≈340 m2/g to ≈240 m2/g; (ii altered the silanol groups on the silica surface; and (iii introduced residual carbon-based surface species to the sample at the highest feed rate. The variations in silica properties altered the (5 wt % nickel deposit characteristics which in turn impacted on the DRM reaction. As the silica surface area increased, the nickel dispersion increased which improved catalyst performance. The residual carbon-based species also appeared to improve nickel dispersion, and in turn catalyst activity, although not to the same extent as the change in silica surface area. The findings illustrate both the importance of silica support characteristics on the catalytic performance of nickel for the DRM reaction and the capacity for using FSP to control these characteristics.

  17. Effect of high surface area activated carbon on thermal degradation of jet fuel

    Energy Technology Data Exchange (ETDEWEB)

    Gergova, K.; Eser, S.; Arumugam, R.; Schobert, H.H. [Pennsylvania State Univ., University Park, PA (United States)

    1995-05-01

    Different solid carbons added to jet fuel during thermal stressing cause substantial changes in pyrolytic degradation reactions. Activated carbons, especially high surface area activated carbons were found to be very effective in suppressing solid deposition on metal reactor walls during stressing at high temperatures (425 and 450{degrees}C). The high surface area activated carbon PX-21 prevented solid deposition on reactor walls even after 5h at 450{degrees}C. The differences seen in the liquid product composition when activated carbon is added indicated that the carbon surfaces affect the degradation reactions. Thermal stressing experiments were carried out on commercial petroleum-derived JPTS jet fuel. We also used n-octane and n-dodecane as model compounds in order to simplify the study of the chemical changes which take place upon activated carbon addition. In separate experiments, the presence of a hydrogen donor, decalin, together with PX-21 was also studied.

  18. Wildland fire emissions, carbon, and climate: Modeling fuel consumption

    Science.gov (United States)

    Roger D. Ottmar

    2014-01-01

    Fuel consumption specifies the amount of vegetative biomass consumed during wildland fire. It is a two-stage process of pyrolysis and combustion that occurs simultaneously and at different rates depending on the characteristics and condition of the fuel, weather, topography, and in the case of prescribed fire, ignition rate and pattern. Fuel consumption is the basic...

  19. Carbon deposition on 20/25/Nb steel using an electrically heated AGR fuel pin

    International Nuclear Information System (INIS)

    Blanchard, A.; Campion, P.

    1980-01-01

    The radiolysis of carbon dioxide in gas-cooled reactors leads to the production of active species capable of reacting with the graphite moderator to form carbon monoxide with a resultant gradual loss of moderator. In the early days of gas-cooled reactor design, the intention was to allow the carbon monoxide concentration to increase and use this reaction product to inhibit the initial radiolysis of the carbon dioxide. Exploratory irradiation experiments using 4 to 7% carbon monoxide revealed that low density deposits ranging in colour from light grey through brown to black were found in the temperature range 470 to 600 K. In view of the fact that this type of deposition could adversely affect heat transfer processes in both fuel channels and heat exchangers, together with the fact that carbon monoxide was not sufficiently powerful as a graphite oxidation inhibitor, methane was selected as the primary inhibitor for the AGR series of power stations. This paper describes some carbon deposition experiments using an electrically heated 'dummy fuel element' linked to a recirculating carbon dioxide irradiation loop in which carbon monoxide concentration, methane concentration, fuel pin temperature and the chemical nature of the fuel pin surface were varied. (author)

  20. Internal reforming of methane in a mono-block-layer build solid oxide fuel cell with an embedding porous pipe: Numerical analysis

    International Nuclear Information System (INIS)

    Ramírez-Minguela, J.J.; Mendoza-Miranda, J.M.; Muñoz-Carpio, V.D.; Rangel-Hernández, V.H.; Pérez-García, V.; Rodríguez-Muñoz, J.L.

    2014-01-01

    Highlights: • A MOLB-type SOFC with different biogas compositions is modeled. • Internal reforming of methane and water gas shift in the anode side are considered. • Changes in the SOFC according to the phenomena inside of them are assessed. • A new configuration for the MOLB-type geometry is proposed. • Temperature gradients effects in the new configuration are significant. - Abstract: A mono-block-layer build type (MOLB-type) geometry, composed with trapezoidal cross-section channels for fuel and air, of solid oxide fuel cell (SOFC), is modeled in this study using a three dimensional computational fluid dynamics (CFD). The model is used to obtain the performance of the SOFC considering internal reforming of methane in the anode side with different biogas compositions. From the results obtained, a new configuration for the MOLB-type geometry is proposed. The model takes into account the mass transfer, heat transfer, species transport, chemical and electrochemical reactions, detailed comparisons of species concentration, temperature and electric fields inside the cell analyzed in the present study. Results show that the biogas from local sludge has the lower temperature gradient and more homogeneous current density distributions along of the fuel cell, on the other hand, with the new configuration proposed for the MOLB-type geometry the temperature distribution inside of the fuel cell has lower temperature gradients

  1. Palliative effects of H2 on SOFCs operating with carbon containing fuels

    Science.gov (United States)

    Reeping, Kyle W.; Bohn, Jessie M.; Walker, Robert A.

    2017-12-01

    Chlorine can accelerate degradation of solid oxide fuel cell (SOFC) Ni-based anodes operating on carbon containing fuels through several different mechanisms. However, supplementing the fuel with a small percentage of excess molecular hydrogen effectively masks the degradation to the catalytic activity of the Ni and carbon fuel cracking reaction reactions. Experiments described in this work explore the chemistry behind the "palliative" effect of hydrogen on SOFCs operating with chlorine-contaminated, carbon-containing fuels using a suite of independent, complementary techniques. Operando Raman spectroscopy is used to monitor carbon accumulation and, by inference, Ni catalytic activity while electrochemical techniques including electrochemical impedance spectroscopy and voltammetry are used to monitor overall cell performance. Briefly, hydrogen not only completely hides degradation observed with chlorine-contaminated carbon-containing fuels, but also actively removes adsorbed chlorine from the surface of the Ni, allowing for the methane cracking reaction to continue, albeit at a slower rate. When hydrogen is removed from the fuel stream the cell fails immediately due to chlorine occupation of methane/biogas reaction sites.

  2. Characterized hydrochar of algal biomass for producing solid fuel through hydrothermal carbonization.

    Science.gov (United States)

    Park, Ki Young; Lee, Kwanyong; Kim, Daegi

    2018-06-01

    The aim of this work was to study the characterized hydrochar of algal biomass to produce solid fuel though hydrothermal carbonization. Hydrothermal carbonization conducted at temperatures ranging from 180 to 270 °C with a 60 min reaction improved the upgrading of the fuel properties and the dewatering of wet-basis biomasses such as algae. The carbon content, carbon recovery, energy recovery, and atomic C/O and C/H ratios in all the hydrochars in this study were improved. These characteristic changes in hydrochar from algal biomass are similar to the coalification reactions due to dehydration and decarboxylation with an increase in the hydrothermal reaction temperature. The results of this study indicate that hydrothermal carbonization can be used as an effective means of generating highly energy-efficient renewable fuel resources using algal biomass. Copyright © 2018 Elsevier Ltd. All rights reserved.

  3. Towards a reference architecture of fuel-based carbon management systems in the logistics industry

    NARCIS (Netherlands)

    Iacob, Maria Eugenia; van Sinderen, Marten J.; Steenwijk, M.; Verkroost, P.

    2013-01-01

    The current practice in the logistics industry is to calculate the carbon footprint of transportation activities based on the distance covered, using long-term fuel consumption averages per kilometer. However, fuel consumption may actually vary over time, because of differences in road

  4. THE INFLUENCE OF CARBON BURNOUT ON SUBMICRON PARTICLE FORMATION FROM EMULSIFIED FUEL OIL COMBUSTION

    Science.gov (United States)

    The paper gives results of an examination of particle behavior and particle size distributions from the combustion of different fuel oils and emulsified fuels in three experimental combusators. Results indicate that improved carbon (C) burnout from fule oil combustion, either by...

  5. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    Energy Technology Data Exchange (ETDEWEB)

    Inui, Y. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)]. E-mail: inui@eee.tut.ac.jp; Urata, A. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Ito, N. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Nakajima, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan); Tanaka, T. [Department of Electrical and Electronic Engineering, Toyohashi University of Technology, Tempaku-cho, Toyohashi 441-8580 (Japan)

    2006-08-15

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide.

  6. Performance simulation of planar SOFC using mixed hydrogen and carbon monoxide gases as fuel

    International Nuclear Information System (INIS)

    Inui, Y.; Urata, A.; Ito, N.; Nakajima, T.; Tanaka, T.

    2006-01-01

    The authors investigate in detail the influence of the mixing ratio of hydrogen and carbon monoxide in the fuel on the cell performance of the SOFC through numerical simulations for a single cell plate of the co-flow type planar cell. It is made clear that the cell performance is almost the same and excellent, independent of the mixing ratio of hydrogen and carbon monoxide under the nominal operating condition. The electromotive force of the hydrogen rich fuel gas is a little higher than that of the carbon monoxide rich fuel gas. The internal voltage drop in the cell decreases as the fraction of carbon monoxide becomes high. Since the value of the single cell voltage is determined by the balance of these two phenomena, the lowering of the electromotive force is dominant and the single cell voltage of the hydrogen rich fuel gas is higher when the inlet gas temperature is high, whereas the voltage drop reduction is dominant and the single cell voltage of the carbon monoxide rich fuel gas is higher when the temperature is low. The effect of the additional gases of water vapor and carbon dioxide is restricted to the single cell voltage shift, and the qualitative dependence of the single cell voltage on the inlet gas temperature is determined by the mixing ratio of hydrogen and carbon monoxide

  7. Technical assessment of a micro-cogeneration system based on polymer electrolyte membrane fuel cell and fluidized bed autothermal reformer

    International Nuclear Information System (INIS)

    Di Marcoberardino, Gioele; Roses, Leonardo; Manzolini, Giampaolo

    2016-01-01

    Highlights: • Performances of an ATR membrane reactor within a PEM FC micro-CHP system of 5 kWel. • Analysis of two different options for the H_2 permeate side: sweep and vacuum pump. • Optimization of operating conditions in terms of efficiency and membrane area. • Distribution of power and thermal consumptions and losses were discussed in detail. • A sensitivity analysis highlights the relevant design parameters of the CHP system. - Abstract: This work investigates the integration of an autothermal membrane reformer within a micro-CHP system of 5 kWel based on PEM fuel cell. The system modeled is based on a prototype developed within Reforcell European project. The optimization of the micro-CHP system is performed from a thermodynamic point of view aiming at the target of 40% of net electric efficiency and 90% of total system efficiency comparing different configuration and operating conditions. In particular, two hydrogen permeate side options as vacuum or sweep steam are evaluated together with different combination of feed temperature and pressures. A good compromise between electric efficiency (40%) and membrane surface area (0.3 m"2) was obtained for the sweep gas case at reaction side conditions of 8 bar, 600 °C and S/C of 2.5. Higher electric efficiency (40.5%) could be achieved by increasing the membrane surface area. The adoption of a vacuum pump simplifies the reactor design and manufacturing, but reduces the net electric efficiency by about 2% points with a membrane surface area of 0.15 m"2. Finally, the sensitivity analysis highlighted the influence of the main parameters and the design criteria for the definition of the CHP system.

  8. Hydrogen generation from natural gas for the fuel cell systems of tomorrow

    Science.gov (United States)

    Dicks, Andrew L.

    In most cases hydrogen is the preferred fuel for use in the present generation of fuel cells being developed for commercial applications. Of all the potential sources of hydrogen, natural gas offers many advantages. It is widely available, clean, and can be converted to hydrogen relatively easily. When catalytic steam reforming is used to generate hydrogen from natural gas, it is essential that sulfur compounds in the natural gas are removed upstream of the reformer and various types of desulfurisation processes are available. In addition, the quality of fuel required for each type of fuel cell varies according to the anode material used, and the cell temperature. Low temperature cells will not tolerate high concentrations of carbon monoxide, whereas the molten fuel cell (MCFC) and solid oxide fuel cell (SOFC) anodes contain nickel on which it is possible to electrochemically oxidise carbon monoxide directly. The ability to internally reform fuel gas is a feature of the MCFC and SOFC. Internal reforming can give benefits in terms of increased electrical efficiency owing to the reduction in the required cell cooling and therefore parasitic system losses. Direct electrocatalysis of hydrocarbon oxidation has been the elusive goal of fuel cell developers over many years and recent laboratory results are encouraging. This paper reviews the principal methods of converting natural gas into hydrogen, namely catalytic steam reforming, autothermic reforming, pyrolysis and partial oxidation; it reviews currently available purification techniques and discusses some recent advances in internal reforming and the direct use of natural gas in fuel cells.

  9. Comparison of high-temperature and low-temperature polymer electrolyte membrane fuel cell systems with glycerol reforming process for stationary applications

    International Nuclear Information System (INIS)

    Authayanun, Suthida; Mamlouk, Mohamed; Scott, Keith; Arpornwichanop, Amornchai

    2013-01-01

    Highlights: • PEMFC systems with a glycerol steam reformer for stationary application are studied. • Performance of HT-PEMFC and LT-PEMFC systems is compared. • HT-PEMFC system shows good performance over LT-PEMFC system at a high current density. • HT-PEMFC system with water gas shift reactor shows the highest system efficiency. • Heat integration can improve the efficiency of HT-PEMFC system. - Abstract: A high-temperature polymer electrolyte membrane fuel cell (HT-PEMFC) has a major advantage over a low-temperature polymer electrolyte fuel cell (LT-PEMFC) demonstrated by a tolerance to a higher CO content in the hydrogen feed and thus a simpler fuel processing. In this study, a direct comparison between the performance of HT-PEMFC and LT-PEMFC systems integrated with a glycerol steam reformer with and without a water gas shift reactor is shown. Under pure hydrogen operation, the LT-PEMFC performance is superior to the HT-PEMFC. However, the HT-PEMFC system shows good performance over the LT-PEMFC system when operated under high current density and high pressure (3 atm) and using the reformate gas derived from the glycerol processor as fuel. At high current density, the high concentration of CO is the major limitation for the operation of HT-PEMFC system without water gas shift reactor, whereas the LT-PEMFC suffers from CO poisoning and restricted oxygen mass transport. Considering the system efficiency with co-heat and power generation, the HT-PEMFC system with water gas shift reactor shows the highest overall system efficiency (approximately 60%) and therefore one of the most suitable technologies for stationary applications

  10. Exergy analysis of the biogas sorption-enhanced chemical looping reforming process integrated with a high-temperature proton exchange membrane fuel cell

    International Nuclear Information System (INIS)

    Kasemanand, Sarunyou; Im-orb, Karittha; Tippawan, Phanicha; Wiyaratn, Wisitsree; Arpornwichanop, Amornchai

    2017-01-01

    Highlights: • A biogas reforming and fuel cell integrated process is considered. • Energy and exergy analyses of the integrated process are performed. • Increasing the nickel oxide-to-biogas ratio decreases the exergy efficiency. • The exergy destruction of the fuel cell increases with increasing cell temperature. • The exergy efficiency of the process is improved when heat integration is applied. - Abstract: A biogas sorption-enhanced chemical looping reforming process integrated with a high-temperature proton exchange membrane fuel cell is analyzed. Modeling of such an integrated process is performed by using a flowsheet simulator (Aspen plus). The exergy analysis is performed to evaluate the energy utilization efficiency of each unit and that of the integrated process. The effect of steam and nickel oxide to biogas ratios on the exergetic performance of the stand-alone biogas sorption-enhanced chemical looping reforming process is investigated. The total exergy destruction increases as the steam or nickel oxide to biogas ratio increases. The main exergy destruction is found at the air reactor. For the high-temperature proton exchange membrane fuel cell, the main exergy destruction is found at the cathode. The total exergy destruction increases when cell temperature increases, whereas the inverse effect is found when the current density is considered as a key parameter. Regarding the exergy efficiency, the results show opposite trend to the exergy destruction. The heat integration analysis is performed to improve the exergetic performance. It is found that the integrated process including the heat integration system can improve the exergy destruction and exergy efficiency of 48% and 60%, respectively.

  11. Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water

    Science.gov (United States)

    Graves, Christopher Ronald

    Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co

  12. Biogas Production from Local Biomass Feedstock in the Mekong Delta and Its Utilization for a Direct Internal Reforming Solid Oxide Fuel Cell

    Directory of Open Access Journals (Sweden)

    Yusuke Shiratori

    2017-05-01

    Full Text Available Fuel-flexible solid oxide fuel cell (SOFC technologies are presently under study in a Vietnam-Japan international joint research project. The purpose of this project is to develop and demonstrate an SOFC-incorporated energy circulation system for the sustainable development of the Mekong Delta region. Lab-scale methane fermentation experiments in this study with a mixture of biomass feedstock collected in the Mekong Delta (shrimp pond sludge, bagasse, and molasses from sugar production recorded biogas production yield over 400 L kgVS−1 with H2S concentration below 50 ppm level. This real biogas was directly supplied to an SOFC without any fuel processing such as desulfurization, methane enrichment and pre-reforming, and stable power generation was achieved by applying paper-structured catalyst (PSC technology.

  13. Effects of fuel and forest conservation on future levels of atmospheric carbon dioxide.

    Science.gov (United States)

    Walker, J C; Kasting, J F

    1992-01-01

    We develop a numerical simulation of the global biogeochemical cycles of carbon that works over time scales extending from years to millions of years. The ocean is represented by warm and cold shallow water reservoirs, a thermocline reservoir, and deep Atlantic, Indian, and Pacific reservoirs. The atmosphere is characterized by a single carbon reservoir and the global biota by a single biomass reservoir. The simulation includes the rock cycle, distinguishing between shelf carbonate and pelagic carbonate precipitation, with distinct lysocline depths in the three deep ocean reservoirs. Dissolution of pelagic carbonates in response to decrease in lysocline depth is included. The simulation is tuned to reproduce the observed radiocarbon record resulting from atomic weapon testing. It is tuned also to reproduce the distribution of dissolved phosphate and total dissolved carbon between the ocean reservoirs as well as the carbon isotope ratios for both 13C and 14C in ocean and atmosphere. The simulation reproduces reasonably well the historical record of carbon dioxide partial pressure as well as the atmospheric isotope ratios for 13C and 14C over the last 200 yr as these have changed in response to fossil fuel burning and land use changes, principally forest clearance. The agreements between observation and calculation involves the assumption of a carbon dioxide fertilization effect in which the rate of production of biomass increases with increasing carbon dioxide partial pressure. At present the fertilization effect of increased carbon dioxide outweighs the effects of forest clearance, so the biota comprises an overall sink of atmospheric carbon dioxide sufficiently large to bring the budget approximately into balance. This simulation is used to examine the future evolution of carbon dioxide and its sensitivity to assumptions about the rate of fossil fuel burning and of forest clearance. Over times extending up to thousands of years, the results are insensitive to the

  14. Development of a solid oxide fuel cell (SOFC) automotive auxiliary power unit (APU) fueled by gasoline

    International Nuclear Information System (INIS)

    DeMinco, C.; Mukerjee, S.; Grieve, J.; Faville, M.; Noetzel, J.; Perry, M.; Horvath, A.; Prediger, D.; Pastula, M.; Boersma, R.; Ghosh, D.

    2000-01-01

    This paper describes the design and the development progress of a 3 to 5 auxiliary power unit (APU) based on a gasoline fueled solid oxide fuel cell (SOFC). This fuel cell was supplied reformate gas (reactant) by a partial oxidation (POx) catalytic reformer utilizing liquid gasoline and designed by Delphi Automotive Systems. This reformate gas consists mainly of hydrogen, carbon monoxide and nitrogen and was fed directly in to the SOFC stack without any additional fuel reformer processing. The SOFC stack was developed by Global Thermoelectric and operates around 700 o C. This automotive APU produces power to support future 42 volt vehicle electrical architectures and loads. The balance of the APU, designed by Delphi Automotive Systems, employs a packaging and insulation design to facilitate installation and operation on-board automobiles. (author)

  15. Power generation using carbon mesh cathodes with different diffusion layers in microbial fuel cells

    KAUST Repository

    Luo, Yong

    2011-11-01

    An inexpensive carbon material, carbon mesh, was examined to replace the more expensive carbon cloth usually used to make cathodes in air-cathode microbial fuel cells (MFCs). Three different diffusion layers were tested using carbon mesh: poly(dimethylsiloxane) (PDMS), polytetrafluoroethylene (PTFE), and Goretex cloth. Carbon mesh with a mixture of PDMS and carbon black as a diffusion layer produced a maximum power density of 1355 ± 62 mW m -2 (normalized to the projected cathode area), which was similar to that obtained with a carbon cloth cathode (1390 ± 72 mW m-2). Carbon mesh with a PTFE diffusion layer produced only a slightly lower (6.6%) maximum power density (1303 ± 48 mW m-2). The Coulombic efficiencies were a function of current density, with the highest value for the carbon mesh and PDMS (79%) larger than that for carbon cloth (63%). The cost of the carbon mesh cathode with PDMS/Carbon or PTFE (excluding catalyst and binder costs) is only 2.5% of the cost of the carbon cloth cathode. These results show that low cost carbon materials such as carbon mesh can be used as the cathode in an MFC without reducing the performance compared to more expensive carbon cloth. © 2011 Elsevier B.V.

  16. Power generation using an activated carbon fiber felt cathode in an upflow microbial fuel cell

    KAUST Repository

    Deng, Qian; Li, Xinyang; Zuo, Jiane.; Ling, Alison; Logan, Bruce E.

    2010-01-01

    An activated carbon fiber felt (ACFF) cathode lacking metal catalysts is used in an upflow microbial fuel cell (UMFC). The maximum power density with the ACFF cathode is 315 mW m-2, compared to lower values with cathodes made of plain carbon paper

  17. Fatty acid methyl esters, carbon nanotubes and carbon nanowalls coatings such as lubricity improvers of low sulfur diesel fuels

    Energy Technology Data Exchange (ETDEWEB)

    Cursaru, Diana Luciana; Tanasescu, Constantin [Petroleum-Gas Univ. of Ploiesti (Romania); Vizireanu, Sorin [National Institute for Laser, Plasma and Radiation Physics (Romania)

    2013-06-01

    In this study the lubricity of diesel fuel was restored by different methods, firstly by classic addition of fatty acid methyl esters or by dispersing carbon nanotubes into diesel fuels and secondly, by protecting the metallic surfaces which are in the direct contact to the low sulfur diesel fuel, by application of solid carbon nanowalls coatings synthesized by radiofrequency plasma beam deposition. The fatty acid methyl esters were prepared by transesterification of the sun flower oil in the presence of methanol. The carbon nanotubes were synthesized by CO disproportionation method and were characterized by RAMAN spectroscopy and high resolution transmission electron microscopy (TEM). The CNWs layers, before the friction tests, were examined by scanning electron microscopy (SEM), atomic force microscopy (AFM) and Raman spectroscopy, while the wear on the steel balls was investigated by optical microscopy of the HRRT apparatus and the wear track on the steel disk was investigated by SEM, AFM and profilometry. The lubricity was measured using the High Frequency Reciprocating Rig (HFRR) method. It has been found that CNWs layers exhibit a lubricating potential for the rubbed surfaces in the presence of low sulfur diesel fuels. Tribological analyses of various carbon materials revealed that the friction coefficient of carbon nanowalls is close to the values obtained for graphite. (orig.)

  18. Applying life-cycle assessment to low carbon fuel standards-How allocation choices influence carbon intensity for renewable transportation fuels

    International Nuclear Information System (INIS)

    Kaufman, Andrew S.; Meier, Paul J.; Sinistore, Julie C.; Reinemann, Douglas J.

    2010-01-01

    The Energy Independence and Security Act (EISA) of 2007 requires life-cycle assessment (LCA) for quantifying greenhouse gas emissions (GHGs) from expanded U.S. biofuel production. To qualify under the Renewable Fuel Standard, cellulosic ethanol and new corn ethanol must demonstrate 60% and 20% lower emissions than petroleum fuels, respectively. A combined corn-grain and corn-stover ethanol system could potentially satisfy a major portion of renewable fuel production goals. This work examines multiple LCA allocation procedures for a hypothetical system producing ethanol from both corn grain and corn stover. Allocation choice is known to strongly influence GHG emission results for corn-ethanol. Stover-derived ethanol production further complicates allocation practices because additional products result from the same corn production system. This study measures the carbon intensity of ethanol fuels against EISA limits using multiple allocation approaches. Allocation decisions are shown to be paramount. Under varying approaches, carbon intensity for corn ethanol was 36-79% that of gasoline, while carbon intensity for stover-derived ethanol was -10% to 44% that of gasoline. Producing corn-stover ethanol dramatically reduced carbon intensity for corn-grain ethanol, because substantially more ethanol is produced with only minor increases in emissions. Regulatory considerations for applying LCA are discussed.

  19. Formulating Energy Policies Related to Fossil Fuel Use: Critical Uncertainties in the Global Carbon Cycle

    Science.gov (United States)

    Post, W. M.; Dale, V. H.; DeAngelis, D. L.; Mann, L. K.; Mulholland, P. J.; O`Neill, R. V.; Peng, T. -H.; Farrell, M. P.

    1990-02-01

    The global carbon cycle is the dynamic interaction among the earth's carbon sources and sinks. Four reservoirs can be identified, including the atmosphere, terrestrial biosphere, oceans, and sediments. Atmospheric CO{sub 2} concentration is determined by characteristics of carbon fluxes among major reservoirs of the global carbon cycle. The objective of this paper is to document the knowns, and unknowns and uncertainties associated with key questions that if answered will increase the understanding of the portion of past, present, and future atmospheric CO{sub 2} attributable to fossil fuel burning. Documented atmospheric increases in CO{sub 2} levels are thought to result primarily from fossil fuel use and, perhaps, deforestation. However, the observed atmospheric CO{sub 2} increase is less than expected from current understanding of the global carbon cycle because of poorly understood interactions among the major carbon reservoirs.

  20. Conversion of hydrocarbons and alcohols for fuel cells

    Science.gov (United States)

    Joensen, Finn; Rostrup-Nielsen, Jens R.

    The growing demand for clean and efficient energy systems is the driving force in the development of fuel processing technology for providing hydrogen or hydrogen-containing gaseous fuels for power generation in fuel cells. Successful development of low cost, efficient fuel processing systems will be critical to the commercialisation of this technology. This article reviews various reforming technologies available for the generation of such fuels from hydrocarbons and alcohols. It also briefly addresses the issue of carbon monoxide clean-up and the question of selecting the appropriate fuel(s) for small/medium scale fuel processors for stationary and automotive applications.

  1. Method for in situ carbon deposition measurement for solid oxide fuel cells

    Science.gov (United States)

    Kuhn, J.; Kesler, O.

    2014-01-01

    Previous methods to measure carbon deposition in solid oxide fuel cell (SOFC) anodes do not permit simultaneous electrochemical measurements. Electrochemical measurements supplemented with carbon deposition quantities create the opportunity to further understand how carbon affects SOFC performance and electrochemical impedance spectra (EIS). In this work, a method for measuring carbon in situ, named here as the quantification of gasified carbon (QGC), was developed. TGA experiments showed that carbon with a 100 h residence time in the SOFC was >99.8% gasified. Comparison of carbon mass measurements between the TGA and QGC show good agreement. In situ measurements of carbon deposition in SOFCs at varying molar steam/carbon ratios were performed to further validate the QGC method, and suppression of carbon deposition with increasing steam concentration was observed, in agreement with previous studies. The technique can be used to investigate in situ carbon deposition and gasification behavior simultaneously with electrochemical measurements for a variety of fuels and operating conditions, such as determining conditions under which incipient carbon deposition is reversible.

  2. Study of a molten carbonate fuel cell combined heat, hydrogen and power system

    International Nuclear Information System (INIS)

    Hamad, Tarek A.; Agll, Abdulhakim A.; Hamad, Yousif M.; Bapat, Sushrut; Thomas, Mathew; Martin, Kevin B.; Sheffield, John W.

    2014-01-01

    To address the problem of fossil fuel usage and high greenhouse gas emissions at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and greenhouse gas emissions. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed the design of CHHP (combined heat, hydrogen and power) system for the campus using local resources. An energy flow and resource availability study is performed to identify the type and source of feedstock required to continuously run the fuel cell system at peak capacity. Following the resource assessment study, the team selects FuelCell Energy DFC (direct fuel cell) 1500™ unit as a molten carbonate fuel cell. The CHHP system provides electricity to power the university campus, thermal energy for heating the anaerobic digester, and hydrogen for transportation, back-up power and other needs. In conclusion, the CHHP system will be able to reduce fossil fuel usage, and greenhouse gas emissions at the university campus. - Highlights: • A molten carbonate fuel cell tri-generation by using anaerobic digestion system. • Anaerobic digestion system will be able to supply fuel for the DFC1500™ unit. • Use locally available feedstock to production electric power, hydrogen and heat. • Application energy end-uses on the university. • CHHP system will reduce energy consumption, fossil fuel usage, and GHG emissions

  3. Utilization of gases from biomass gasification in a reforming reactor coupled to an integrated planar solid oxide fuel cell: Simulation analysis

    Directory of Open Access Journals (Sweden)

    Costamagna Paola

    2004-01-01

    Full Text Available One of the high-efficiency options currently under study for a rational employment of hydrogen are fuel cells. In this scenario, the integrated planar solid oxide fuel cell is a new concept recently proposed by Rolls-Royce. The basic unit of a modular plant is the so called "strip", containing an electro-chemical reactor formed by a number of IP-SOFC modules, and a reforming reactor. For a better under standing of the behavior of a system of this kind, a simulation model has been set up for both the electrochemical reactor and the reformer; both models follow the approach typically employed in the simulation of chemical reactors, based on the solution of mass and energy balances. In the case of the IP-SOFC electro chemical reactor, the model includes the calculation of the electrical resistance of the stack (that is essentially due to ohmic losses, activation polar is action and mass transport limitations, the mass balances of the gaseous flows, the energy balances of gaseous flows (anodic and cathodic and of the solid. The strip is designed in such a way that the reaction in the reforming reactor is thermally sustained by the sensible heat of the hot air exiting the electrochemical section; this heat exchange is taken into account in the model of the reformer, which includes the energy balance of gaseous flows and of the solid structure. Simulation results are reported and discussed for both the electrochemical reactor in stand-alone configuration (including comparison to experimental data in a narrow range of operating conditions and for the complete strip.

  4. A synthesis of carbon dioxide emissions from fossil-fuel combustion

    DEFF Research Database (Denmark)

    Andres, R.J.; Boden, T.A.; Bréon, F.-M.

    2012-01-01

    This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores our knowledge of these emissions in terms......; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions......, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossilfuel carbon dioxide emissions are known to within 10% uncertainty (95% confidence interval). Uncertainty on individual national total fossil-fuel carbon...

  5. Porous Carbon Materials for Elements in Low-Temperature Fuel Cells

    Directory of Open Access Journals (Sweden)

    Wlodarczyk R.

    2015-04-01

    Full Text Available The porosity, distribution of pores, shape of pores and specific surface area of carbon materials were investigated. The study of sintered graphite and commercial carbon materials used in low-temperature fuel cells (Graphite Grade FU, Toray Teflon Treated was compared. The study covered measurements of density, microstructural examinations and wettability (contact angle of carbon materials. The main criterion adopted for choosing a particular material for components of fuel cells is their corrosion resistance under operating conditions of hydrogen fuel cells. In order to determine resistance to corrosion in the environment of operation of fuel cells, potentiokinetic curves were registered for synthetic solution 0.1M H2SO4+ 2 ppmF-at 80°C.

  6. 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

    .... Our approach to solve the military waste disposal and fuel supply problems was to convert the waste to a liquid fuel that can be used in place of or blended with conventional logistic fuels, particularly JP-8...

  7. Rapid fuel switching from coal to natural gas through effective carbon pricing

    Science.gov (United States)

    Wilson, I. A. Grant; Staffell, Iain

    2018-05-01

    Great Britain's overall carbon emissions fell by 6% in 2016, due to cleaner electricity production. This was not due to a surge in low-carbon nuclear or renewable sources; instead it was the much-overlooked impact of fuel switching from coal to natural gas generation. This Perspective considers the enabling conditions in Great Britain and the potential for rapid fuel switching in other coal-reliant countries. We find that spare generation and fuel supply-chain capacity must already exist for fuel switching to deliver rapid carbon savings, and to avoid further high-carbon infrastructure lock-in. More important is the political will to alter the marketplace and incentivize this switch, for example, through a stable and strong carbon price. With the right incentives, fuel switching in the power sector could rapidly achieve on the order of 1 GtCO2 saving per year worldwide (3% of global emissions), buying precious time to slow the growth in cumulative carbon emissions.

  8. Synthetic fuel production via carbon neutral cycles with high temperature nuclear reactors as a power source

    Energy Technology Data Exchange (ETDEWEB)

    Konarek, E.; Coulas, B.; Sarvinis, J. [Hatch Ltd., Mississauga, Ontario (Canada)

    2016-06-15

    This paper analyzes a number of carbon neutral cycles, which could be used to produce synthetic hydrocarbon fuels. Synthetic hydrocarbons are produced via the synthesis of Carbon Monoxide and Hydrogen. The . cycles considered will either utilize Gasification processes, or carbon capture as a source of feed material. In addition the cycles will be coupled to a small modular Nuclear Reactor (SMR) as a power and heat source. The goal of this analysis is to reduce or eliminate the need to transport diesel and other fossil fuels to remote regions and to provide a carbon neutral, locally produced hydrocarbon fuel for remote communities. The technical advantages as well as the economic case are discussed for each of the cycles presented. (author)

  9. Synthetic fuel production via carbon neutral cycles with high temperature nuclear reactors as a power source

    International Nuclear Information System (INIS)

    Konarek, E.; Coulas, B.; Sarvinis, J.

    2016-01-01

    This paper analyzes a number of carbon neutral cycles, which could be used to produce synthetic hydrocarbon fuels. Synthetic hydrocarbons are produced via the synthesis of Carbon Monoxide and Hydrogen. The . cycles considered will either utilize Gasification processes, or carbon capture as a source of feed material. In addition the cycles will be coupled to a small modular Nuclear Reactor (SMR) as a power and heat source. The goal of this analysis is to reduce or eliminate the need to transport diesel and other fossil fuels to remote regions and to provide a carbon neutral, locally produced hydrocarbon fuel for remote communities. The technical advantages as well as the economic case are discussed for each of the cycles presented. (author)

  10. Residential carbon dioxide emissions in Canada. Impact of efficiency improvements and fuel substitution

    International Nuclear Information System (INIS)

    Ugursal, V.I.; FUng, A.S.

    1998-01-01

    The effect of improving house envelope, heating system and appliance efficiencies, and fuel substitution on the atmospheric emissions of carbon dioxide in the Canadian residential sector is studied based on simulation studies. The findings clearly indicate that improving appliance efficiency reduces the overall end-use energy consumption in the residential sector as well as the associated carbon dioxide emissions. However, the magnitude of the reduction in carbon dioxide emissions as a result of improving only appliance efficiencies is quite small. Significantly larger reductions can be obtained by improving house envelopes and heating/cooling systems in addition to improving appliance efficiencies. Fuel substitution for space and domestic hot water heating can also present a potential to reduce carbon dioxide emissions depending on the fuel substitution scenario adopted. (author)

  11. Effects of coal-derived trace species on performance of molten carbonate fuel cells. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The Carbonate Fuel Cell is a very promising option for highly efficient generation of electricity from many fuels. If coal-gas is to be used, the interactions of coal-derived impurities on various fuel cell components need to be understood. Thus the effects on Carbonate Fuel Cell performance due to ten different coal-derived contaminants viz., NH{sub 3}, H{sub 2}S, HC{ell}, H{sub 2}Se, AsH{sub 3}, Zn, Pb, Cd, Sn, and Hg, have been studied at Energy Research Corporation. Both experimental and theoretical evaluations were performed, which have led to mechanistic insights and initial estimation of qualitative tolerance levels for each species individually and in combination with other species. The focus of this study was to investigate possible coal-gas contaminant effects on the anode side of the Carbonate Fuel Cell, using both out-of-cell thermogravimetric analysis by isothermal TGA, and fuel cell testing in bench-scale cells. Separate experiments detailing performance decay in these cells with high levels of ammonia contamination (1 vol %) and with trace levels of Cd, Hg, and Sn, have indicated that, on the whole, these elements do not affect carbonate fuel cell performance. However, some performance decay may result when a number of the other six species are present, singly or simultaneously, as contaminants in fuel gas. In all cases, tolerance levels have been estimated for each of the 10 species and preliminary models have been developed for six of them. At this stage the models are limited to isothermal, benchscale (300 cm{sup 2} size) single cells. The information obtained is expected to assist in the development of coal-gas cleanup systems, while the contaminant performance effects data will provide useful basic information for modeling fuel cell endurance in conjunction with integrated gasifier/fuel-cell systems (IGFC).

  12. Effects of coal-derived trace species on performance of molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    1992-05-01

    The Carbonate Fuel Cell is a very promising option for highly efficient generation of electricity from many fuels. If coal-gas is to be used, the interactions of coal-derived impurities on various fuel cell components need to be understood. Thus the effects on Carbonate Fuel Cell performance due to ten different coal-derived contaminants viz., NH{sub 3}, H{sub 2}S, HC{ell}, H{sub 2}Se, AsH{sub 3}, Zn, Pb, Cd, Sn, and Hg, have been studied at Energy Research Corporation. Both experimental and theoretical evaluations were performed, which have led to mechanistic insights and initial estimation of qualitative tolerance levels for each species individually and in combination with other species. The focus of this study was to investigate possible coal-gas contaminant effects on the anode side of the Carbonate Fuel Cell, using both out-of-cell thermogravimetric analysis by isothermal TGA, and fuel cell testing in bench-scale cells. Separate experiments detailing performance decay in these cells with high levels of ammonia contamination (1 vol %) and with trace levels of Cd, Hg, and Sn, have indicated that, on the whole, these elements do not affect carbonate fuel cell performance. However, some performance decay may result when a number of the other six species are present, singly or simultaneously, as contaminants in fuel gas. In all cases, tolerance levels have been estimated for each of the 10 species and preliminary models have been developed for six of them. At this stage the models are limited to isothermal, benchscale (300 cm{sup 2} size) single cells. The information obtained is expected to assist in the development of coal-gas cleanup systems, while the contaminant performance effects data will provide useful basic information for modeling fuel cell endurance in conjunction with integrated gasifier/fuel-cell systems (IGFC).

  13. Fuel flexibility within a carbon limited energy world

    Energy Technology Data Exchange (ETDEWEB)

    Jones, R.M.; Raddings, T.; Scholz, M. [GE Energy (United States)

    2007-07-01

    This paper focuses on technical aspects of Integrated Gasification Combined Cycles (IGCC) from a coal, pre-combustion perspective, now and towards the future, including gasification and hydrogen gas turbines. The advantages of gasification and pre-combustion fuel clean-up range from the potential to utilize various low cost feedstock, which can be converted into synthetic fuels, to providing a viable and secure alternative to natural gas. GE has delivered over 650 licensed gasification facilities operational in the field, 12 with solid feedstock and 25 utilizing shift reaction for hydrogen production and CO{sub 2} capture. The process for pre-combustion de-carbonisation of natural gas or syngas derived from coals will result in gas turbine fuels that consist of 90% or higher hydrogen content fuel. Over 25 GE heavy-duty gas turbines are operating presently, on a large variation of syngas fuels, ranging from B and E to F-class technologies. 7 refs., 15 figs.

  14. Renewable hydrogen: carbon formation on Ni and Ru catalysts during ethanol steam-reforming

    DEFF Research Database (Denmark)

    Rass-Hansen, Jeppe; Christensen, Christina Hviid; Sehested, J.

    2007-01-01

    for the production of hydrogen is investigated, along with quantitative and qualitative determinations of carbon formation on the catalysts by TPO and TEM experiments. A Ru/ MgAl2O4 catalyst, a Ni/MgAl2O4 catalyst as well as Ag-and K-promoted Ni/ MgAl2O4 catalysts were studied. The operating temperature was between...... addition was a rapid deactivation of the catalyst due to an enhanced gum carbon formation on the Ni crystals. Contrary to this, the effect of K addition was a prolonged resistance against carbon formation and therefore against deactivation. The Ru catalyst operates better than all the Ni catalysts...

  15. Plasma devices for hydrocarbon reformation

    KAUST Repository

    Cha, Min Suk

    2017-02-16

    Plasma devices for hydrocarbon reformation are provided. Methods of using the devices for hydrocarbon reformation are also provided. The devices can include a liquid container to receive a hydrocarbon source, and a plasma torch configured to be submerged in the liquid. The plasma plume from the plasma torch can cause reformation of the hydrocarbon. The device can use a variety of plasma torches that can be arranged in a variety of positions in the liquid container. The devices can be used for the reformation of gaseous hydrocarbons and/or liquid hydrocarbons. The reformation can produce methane, lower hydrocarbons, higher hydrocarbons, hydrogen gas, water, carbon dioxide, carbon monoxide, or a combination thereof.

  16. A synthesis of carbon dioxide emissions from fossil-fuel combustion

    Directory of Open Access Journals (Sweden)

    R. J. Andres

    2012-05-01

    Full Text Available This synthesis discusses the emissions of carbon dioxide from fossil-fuel combustion and cement production. While much is known about these emissions, there is still much that is unknown about the details surrounding these emissions. This synthesis explores our knowledge of these emissions in terms of why there is concern about them; how they are calculated; the major global efforts on inventorying them; their global, regional, and national totals at different spatial and temporal scales; how they are distributed on global grids (i.e., maps; how they are transported in models; and the uncertainties associated with these different aspects of the emissions. The magnitude of emissions from the combustion of fossil fuels has been almost continuously increasing with time since fossil fuels were first used by humans. Despite events in some nations specifically designed to reduce emissions, or which have had emissions reduction as a byproduct of other events, global total emissions continue their general increase with time. Global total fossil-fuel carbon dioxide emissions are known to within 10 % uncertainty (95 % confidence interval. Uncertainty on individual national total fossil-fuel carbon dioxide emissions range from a few percent to more than 50 %. This manuscript concludes that carbon dioxide emissions from fossil-fuel combustion continue to increase with time and that while much is known about the overall characteristics of these emissions, much is still to be learned about the detailed characteristics of these emissions.

  17. Natural gas reforming of carbon dioxide for syngas over Ni–Ce–Al catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jun; Zhan, Yiqiu; Street, Jason; To, Filip; Yu, Fei

    2017-07-01

    A series of Ni–Ce–Al composite oxides with various Ni molar contents were synthesized via the refluxed co-precipitation method and used for natural gas reforming of CO2 (NGRC) for syngas production. The effect of Ni molar content, reaction temperature, feed gas ratio and gas hourly space velocity (GHSV) on the Ni–Ce–Al catalytic performance was investigated. The Ni10CeAl catalyst was selected to undergo 30 h stability test and the conversion of CH4 and CO2 decreased by 2.8% and 2.6%, respectively. The characterization of the reduced and used Ni10CeAl catalyst was performed using BET, H2-TPR, in-situ XRD, TEM, and TGA-DTG techniques. The in-situ XRD results revealed that Ce2O3, CeO2 and CeAlO3 coexisted in the Ni10CeAl catalyst after reduction at 850 °C for 2 h. The results of the TEM analysis revealed that the Ni particle size increased after the NGRC reaction, which mainly caused the catalyst deactivation.

  18. hydrogel membrane as electrolyte for direct borohydride fuel cells

    Indian Academy of Sciences (India)

    Administrator

    and hence attractive energy sources for future gene- ration. Among the various types of fuel cells, poly- mer electrolyte fuel cells (PEFCs) are especially promising due to their quick start-up capabilities under ambient conditions. But PEFCs suffer from carbon monoxide poisoning of platinum anode. 1–3 while using reformer ...

  19. Degradation Mechanism in a Direct Carbon Fuel Cell Operated with Demineralised Brown Coal

    International Nuclear Information System (INIS)

    Rady, Adam C.; Giddey, Sarbjit; Kulkarni, Aniruddha; Badwal, Sukhvinder P.S.; Bhattacharya, Sankar

    2014-01-01

    Graphical abstract: - Highlights: • Degradation mechanism studied for demineralised coal in a direct carbon fuel cell. • Diffusion limited processes dominate the electrode polarisation losses in pure N 2 . • Major fuel cell performance loss occurred due to loss of carbon/anode contacts. • The anode retained its phase structure with minor other phases formed in operation. - Abstract: The performance of a demineralised and devolatilised coal from the Morwell mine in the Latrobe Valley, Victoria, has been investigated in a direct carbon fuel cell (DCFC) operated at 850 °C. The focus of the investigation has been on understanding degradation issues as a function of time involving a sequence of electrochemical impedance spectroscopy and voltage-current characteristic. Diffusion limited processes dominate the electrode polarisation losses in pure N 2 atmosphere, however, these decrease substantially in the presence of CO 2 as the anode chamber purge gas, due to in situ generation of fuel species by the reaction of CO 2 with carbon. Post-mortem analysis of anode by SEM and XRD revealed only a minor degradation due to its reduction, particle agglomeration as well as the formation of small quantity of new phases. However, major fuel cell performance degradation (increase of ohmic resistive and electrode polarisation losses) occurred due to loss of carbon/anode contacts and a reduction in the electron-conducting pathways as the fuel was consumed. The investigations revealed that the demineralised coal char can be used as a viable fuel for DCFC, however, further developments on anode materials and fuel feed mechanism would be required to achieve long-term sustained performance

  20. Enhanced Activated Carbon Cathode Performance for Microbial Fuel Cell by Blending Carbon Black

    KAUST Repository

    Zhang, Xiaoyuan; Xia, Xue; Ivanov, Ivan; Huang, Xia; Logan, Bruce E.

    2014-01-01

    Activated carbon (AC) is a useful and environmentally sustainable catalyst for oxygen reduction in air-cathode microbial fuel cells (MFCs), but there is great interest in improving its performance and longevity. To enhance the performance of AC cathodes, carbon black (CB) was added into AC at CB:AC ratios of 0, 2, 5, 10, and 15 wt % to increase electrical conductivity and facilitate electron transfer. AC cathodes were then evaluated in both MFCs and electrochemical cells and compared to reactors with cathodes made with Pt. Maximum power densities of MFCs were increased by 9-16% with CB compared to the plain AC in the first week. The optimal CB:AC ratio was 10% based on both MFC polarization tests and three electrode electrochemical tests. The maximum power density of the 10% CB cathode was initially 1560 ± 40 mW/m2 and decreased by only 7% after 5 months of operation compared to a 61% decrease for the control (Pt catalyst, 570 ± 30 mW/m2 after 5 months). The catalytic activities of Pt and AC (plain or with 10% CB) were further examined in rotating disk electrode (RDE) tests that minimized mass transfer limitations. The RDE tests showed that the limiting current of the AC with 10% CB was improved by up to 21% primarily due to a decrease in charge transfer resistance (25%). These results show that blending CB in AC is a simple and effective strategy to enhance AC cathode performance in MFCs and that further improvement in performance could be obtained by reducing mass transfer limitations. © 2014 American Chemical Society.

  1. Enhanced Activated Carbon Cathode Performance for Microbial Fuel Cell by Blending Carbon Black

    KAUST Repository

    Zhang, Xiaoyuan

    2014-02-04

    Activated carbon (AC) is a useful and environmentally sustainable catalyst for oxygen reduction in air-cathode microbial fuel cells (MFCs), but there is great interest in improving its performance and longevity. To enhance the performance of AC cathodes, carbon black (CB) was added into AC at CB:AC ratios of 0, 2, 5, 10, and 15 wt % to increase electrical conductivity and facilitate electron transfer. AC cathodes were then evaluated in both MFCs and electrochemical cells and compared to reactors with cathodes made with Pt. Maximum power densities of MFCs were increased by 9-16% with CB compared to the plain AC in the first week. The optimal CB:AC ratio was 10% based on both MFC polarization tests and three electrode electrochemical tests. The maximum power density of the 10% CB cathode was initially 1560 ± 40 mW/m2 and decreased by only 7% after 5 months of operation compared to a 61% decrease for the control (Pt catalyst, 570 ± 30 mW/m2 after 5 months). The catalytic activities of Pt and AC (plain or with 10% CB) were further examined in rotating disk electrode (RDE) tests that minimized mass transfer limitations. The RDE tests showed that the limiting current of the AC with 10% CB was improved by up to 21% primarily due to a decrease in charge transfer resistance (25%). These results show that blending CB in AC is a simple and effective strategy to enhance AC cathode performance in MFCs and that further improvement in performance could be obtained by reducing mass transfer limitations. © 2014 American Chemical Society.

  2. Reduced carbon emission estimates from fossil fuel combustion and cement production in China.

    Science.gov (United States)

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Marland, Gregg; Andres, Robert J; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng; Boden, Thomas A; Feng, Kuishuang; Peters, Glen P; Xi, Fengming; Liu, Junguo; Li, Yuan; Zhao, Yu; Zeng, Ning; He, Kebin

    2015-08-20

    Nearly three-quarters of the growth in global carbon emissions from the burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 differ by 0.3 gigatonnes of carbon, or 15 per cent. The primary sources of this uncertainty are conflicting estimates of energy consumption and emission factors, the latter being uncertain because of very few actual measurements representative of the mix of Chinese fuels. Here we re-evaluate China's carbon emissions using updated and harmonized energy consumption and clinker production data and two new and comprehensive sets of measured emission factors for Chinese coal. We find that total energy consumption in China was 10 per cent higher in 2000-2012 than the value reported by China's national statistics, that emission factors for Chinese coal are on average 40 per cent lower than the default values recommended by the Intergovernmental Panel on Climate Change, and that emissions from China's cement production are 45 per cent less than recent estimates. Altogether, our revised estimate of China's CO2 emissions from fossil fuel combustion and cement production is 2.49 gigatonnes of carbon (2 standard deviations = ±7.3 per cent) in 2013, which is 14 per cent lower than the emissions reported by other prominent inventories. Over the full period 2000 to 2013, our revised estimates are 2.9 gigatonnes of carbon less than previous estimates of China's cumulative carbon emissions. Our findings suggest that overestimation of China's emissions in 2000-2013 may be larger than China's estimated total forest sink in 1990-2007 (2.66 gigatonnes of carbon) or China's land carbon sink in 2000-2009 (2.6 gigatonnes of carbon).

  3. Short and long-term carbon balance of bioenergy electricity production fueled by forest treatments.

    Science.gov (United States)

    Kelsey, Katharine C; Barnes, Kallie L; Ryan, Michael G; Neff, Jason C

    2014-01-01

    Forests store large amounts of carbon in forest biomass, and this carbon can be released to the atmosphere following forest disturbance or management. In the western US, forest fuel reduction treatments designed to reduce the risk of high severity wildfire can change forest carbon balance by removing carbon in the form of biomass, and by altering future potential wildfire behavior in the treated stand. Forest treatment carbon balance is further affected by the fate of this biomass removed from the forest, and the occurrence and intensity of a future wildfire in this stand. In this study we investigate the carbon balance of a forest treatment with varying fates of harvested biomass, including use for bioenergy electricity production, and under varying scenarios of future disturbance and regeneration. Bioenergy is a carbon intensive energy source; in our study we find that carbon emissions from bioenergy electricity production are nearly twice that of coal for the same amount of electricity. However, some emissions from bioenergy electricity production are offset by avoided fossil fuel electricity emissions. The carbon benefit achieved by using harvested biomass for bioenergy electricity production may be increased through avoided pyrogenic emissions if the forest treatment can effectively reduce severity. Forest treatments with the use of harvested biomass for electricity generation can reduce carbon emissions to the atmosphere by offsetting fossil fuel electricity generation emissions, and potentially by avoided pyrogenic emissions due to reduced intensity and severity of a future wildfire in the treated stand. However, changes in future wildfire and regeneration regimes may affect forest carbon balance and these climate-induced changes may influence forest carbon balance as much, or more, than bioenergy production.

  4. 40 CFR 600.208-12 - Calculation of FTP-based and HFET-based fuel economy and carbon-related exhaust emission values...

    Science.gov (United States)

    2010-07-01

    ...-based fuel economy and carbon-related exhaust emission values for a model type. 600.208-12 Section 600... ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF MOTOR VEHICLES Fuel Economy Regulations for 1977 and Later...-based and HFET-based fuel economy and carbon-related exhaust emission values for a model type. (a) Fuel...

  5. Carbon Monitoring System Flux for Fossil Fuel L4 V1 (CMSFluxFossilfuel) at GES DISC

    Data.gov (United States)

    National Aeronautics and Space Administration — This dataset provides the Carbon Flux for Fossil Fuel. The NASA Carbon Monitoring System (CMS) is designed to make significant contributions in characterizing,...

  6. Life cycle inventory analysis of hydrogen production by the steam-reforming process: comparison between vegetable oils and fossil fuels as feedstock

    International Nuclear Information System (INIS)

    Marquevich, M.; Sonnemann, G.W.; Castells, F.; Montane, D.

    2002-01-01

    A life cycle inventory analysis has been conducted to assess the environmental load, specifically CO 2 (fossil) emissions and global warming potential (GWP), associated to the production of hydrogen by the steam reforming of hydrocarbon feedstocks (methane and naphtha) and vegetable oils (rapeseed oil, soybean oil and palm oil). Results show that the GWPs associated with the production of hydrogen by steam reforming in a 100 years time frame are 9.71 and 9.46 kg CO 2 -equivalent/kg H 2 for natural gas and naphtha, respectively. For vegetable oils, the GWP decreases to 6.42 kg CO 2 -equivalent/kg H 2 for rapeseed oil, 4.32 for palm oil and 3.30 for soybean oil. A dominance analysis determined that the part of the process that has the largest effect on the GWP is the steam reforming reaction itself for the fossil fuel-based systems, which accounts for 56.7% and 74% of the total GWP for natural gas and naphtha, respectively. This contribution is zero for vegetable oil-based systems, for which harvesting and oil production are the main sources of CO 2 -eq emissions.(author)

  7. Tendances Carbone no. 78 'Reforming the EU ETS: give it some work'

    International Nuclear Information System (INIS)

    Sartor, Oliver; Berghmans, Nicolas; Stephan, Nicolas

    2013-01-01

    Among the publications of CDC Climat Research, 'Tendances Carbone' bulletin specifically studies the developments of the European market for CO 2 allowances. This issue addresses the following points: The Carbon Market Report published last November by the European Commission launched a debate on structural measures to sustainably address the EU ETS's large surplus and sets out six options for measures which could do so: (a) increasing the EU reduction target to 30% in 2020, (b) retiring a number of allowances in phase 3, (c) early revision of the annual linear reduction factor, (d) extension of the EU ETS to other sectors, (e) limit access to international credits, (f) discretionary price management mechanisms. To assess these options, we must ask: what needs to be improved about the EU ETS's current design?

  8. Removal of carbon dioxide in reprocessing spent nuclear fuel off gas by adsorption

    International Nuclear Information System (INIS)

    Fukumatsu, Teruki; Munakata, Kenzo; Tanaka, Kenji; Yamatsuki, Satoshi; Nishikawa, Masabumi

    1998-01-01

    The off gas produced by reprocessing spent nuclear fuel includes various radioactivities and these nuclei should be removed. In particular, 14 C mainly released as the form of carbon dioxide is one of the most required gaseous radioactivities to be removed because it has long a half-life. One of the methods to remove gaseous nuclei is the use of adsorption technique. The off gas contains water vapor which influences adsorption process of carbon dioxide. In this report, behavior of adsorption of carbon dioxide on various adsorbent and influence on adsorption behavior of carbon dioxide by containing water vapor are discussed. (author)

  9. A natural-gas fuel processor for a residential fuel cell system

    Science.gov (United States)

    Adachi, H.; Ahmed, S.; Lee, S. H. D.; Papadias, D.; Ahluwalia, R. K.; Bendert, J. C.; Kanner, S. A.; Yamazaki, Y.

    A system model was used to develop an autothermal reforming fuel processor to meet the targets of 80% efficiency (higher heating value) and start-up energy consumption of less than 500 kJ when operated as part of a 1-kWe natural-gas fueled fuel cell system for cogeneration of heat and power. The key catalytic reactors of the fuel processor - namely the autothermal reformer, a two-stage water gas shift reactor and a preferential oxidation reactor - were configured and tested in a breadboard apparatus. Experimental results demonstrated a reformate containing ∼48% hydrogen (on a dry basis and with pure methane as fuel) and less than 5 ppm CO. The effects of steam-to-carbon and part load operations were explored.

  10. Integrated high-efficiency Pt/carbon nanotube arrays for PEM fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Weimin; Minett, Andrew I.; Zhao, Jie; Razal, Joselito M.; Wallace, Gordon G.; Romeo, Tony; Chen, Jun [Intelligent Polymer Research Institute, AIIM Facility, Innovation Campus, University of Wollongong, NSW 2522 (Australia); Gao, Mei [Division of Materials Science and Engineering, CSIRO, Bayview Ave, Clayton, VIC 3168 (Australia)

    2011-07-15

    A facile strategy to deposit Pt nanoparticles with various metal-loading densities on vertically aligned carbon nanotube (ACNT) arrays as electrocatalysts for proton exchange membrane (PEM) fuel cells is described. The deposition is achieved by electrostatic adsorption of the Pt precursor on the positively charged polyelectrolyte functionalized ACNT arrays and subsequent reduction by L-ascorbic acid. The application of the aligned electrocatalysts in fuel cells is realized by transferring from a quartz substrate to nafion membrane using a hot-press procedure to fabricate the membrane electrode assembly (MEA). It is shown that the MEA with vertically aligned structured electrocatalysts provides better Pt utilization than that with Pt on conventional carbon nanotubes or carbon black, resulting in higher fuel cell performance. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Utilization of corn cob biochar in a direct carbon fuel cell

    Science.gov (United States)

    Yu, Jinshuai; Zhao, Yicheng; Li, Yongdan

    2014-12-01

    Biochar obtained from the pyrolysis of corn cob is used as the fuel of a direct carbon fuel cell (DCFC) employing a composite electrolyte composed of a samarium doped ceria (SDC) and a eutectic carbonate phase. An anode layer made of NiO and SDC is utilized to suppress the cathode corrosion by the molten carbonate and improves the whole cell stability. The anode off-gas of the fuel cell is analyzed with a gas chromatograph. The effect of working temperature on the cell resistance and power output is examined. The maximum power output achieves 185 mW cm-2 at a current density of 340 mA cm-2 and 750 °C. An anode reaction scheme including the Boudouard reaction is proposed.

  12. Carbon dioxide emission index as a mean for assessing fuel quality

    Energy Technology Data Exchange (ETDEWEB)

    Furimsky, E. [IMAF Group, Ottawa, ON (Canada)

    2008-07-01

    Carbon dioxide emission index, defined as the amount of CO{sub 2} released per unit of energy value, was used to rate gaseous, liquid and solid fuels. The direct utilization of natural gas is the most efficient option. The conversion of natural gas to synthesis gas for production of liquid fuels represents a significant decrease in fuel value of the former. The fuel value of liquids, such as gasoline, diesel oil, etc. is lower than that of natural gas. Blending gasoline with ethanol obtained either from bio-mass or via synthesis may decrease fuel value of the blend when CO{sub 2} emissions produced during the production of ethanol are included in total emissions. The introduction of liquid fuels produced by pyrolysis and liquefaction of biomass would result in the increase in the CO{sub 2} emissions. The CO{sub 2} emissions from the utilization of coal and petroleum coke are much higher than those from gaseous and liquid fuels. However, for petroleum coke, this is offset by the high value gaseous and liquid fuels that are simultaneously produced during coking. Conversion of low value fuels such as coal and petroleum coke to a high value chemicals via synthesis gas should be assessed as means for replacing natural gas and making it available for fuel applications.

  13. Effects of coal-derived trace species on the performance of molten carbonate fuel cells

    Energy Technology Data Exchange (ETDEWEB)

    Pigeaud, A.

    1991-10-01

    The overall objective of the present study was to determine in detail the interaction effects of 10 simultaneously present, coal-gas contaminants, both on each other and on components of the Carbonate Fuel Cell. The primary goal was to assess underlying chemistries and reaction mechanisms which may cause decay in fuel cell performance or endurance as a result of both physics-chemical and/or mechanical interactions with the cell components and internal fuel cell parts. It was found, both from theory and cell test evidence, that trace contaminant interactions may occur with: Fuel-cell Electrodes (e.g., in this study with the Ni-anode), Lithium/Potassium Carbonate Electrolyte, Nickel and SS-Hardware, and by Mechanical Obstruction of Gas Flow in the Anode Plenum.

  14. Fabrication and properties of carbon network reinforced composite fuel

    International Nuclear Information System (INIS)

    Umer, Malik Adeel; Mistarihi, Qusai Mahmoud; Kim, Joon Hui; Hong, Soon Hyung; Ryu, Ho Jin

    2014-01-01

    Zirconium dioxide composites reinforced with 3D glassy carbon foam was fabricated using Spark Plasma Sintering (SPS) with a heating rate of 100degC/min and a uniaxial pressure of 50 MPa at 1500degC, 1600degC, and 1700degC, respectively. The effect of carbon foam on the thermal properties of the ZrO 2 composites was investigated. In addition, the effect of the sintering temperature on the densification of the composites was also investigated and the optimized sintering temperature was identified. The microstructures of 3D carbon foam reinforced ZrO 2 composites showed that the 3D shape of carbon foam was retained after the sintering process, and the ZrO 2 was homogeneously distributed within the 3D carbon foam. At the interfaces between the 3D carbon foam and ZrO 2 , neither a chemical reaction nor a new phase formation was detected by Scanning Electron Microscopy (SEM) and X-ray Diffractometry (XRD). The thermal diffusivity of carbon foam reinforced ZrO 2 composites measured at 1100degC was increased by 47% and reached to 0.66 mm 2 s -1 and the thermal conductivity was increased by 50% and reached to 2.428 W/m-K. (author)

  15. Carbon-coated ceramic membrane reactor for the production of hydrogen by aqueous-phase reforming of sorbitol.

    Science.gov (United States)

    Neira D'Angelo, M F; Ordomsky, V; Schouten, J C; van der Schaaf, J; Nijhuis, T A

    2014-07-01

    Hydrogen was produced by aqueous-phase reforming (APR) of sorbitol in a carbon-on-alumina tubular membrane reactor (4 nm pore size, 7 cm long, 3 mm internal diameter) that allows the hydrogen gas to permeate to the shell side, whereas the liquid remains in the tube side. The hydrophobic nature of the membrane serves to avoid water loss and to minimize the interaction between the ceramic support and water, thus reducing the risks of membrane degradation upon operation. The permeation of hydrogen is dominated by the diffusivity of the hydrogen in water. Thus, higher operation temperatures result in an increase of the flux of hydrogen. The differential pressure has a negative effect on the flux of hydrogen due to the presence of liquid in the larger pores. The membrane was suitable for use in APR, and yielded 2.5 times more hydrogen than a reference reactor (with no membrane). Removal of hydrogen through the membrane assists in the reaction by preventing its consumption in undesired reactions. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Cost analysis of electrical power from an ethanol reformer and the fuel cell in the development of productive activities in the community Pico do Amor, MT, Brazil

    International Nuclear Information System (INIS)

    Lopes, Davi Gabriel; Teixeira, Andre Frazao; Lopes, Daniel Gabriel; Cavaliero, Carla Kazue Nakao

    2010-01-01

    This work has the objective to analyze the impact of the cost of from an ethane reformer / fuel cell in the family income considering the development of two productive activities selected by the community itself: the production and marketing of cassava flour and 'rapadura', a typical brazilian candy. The community energy demand was analyzed to achieve the results; estimated the energy cost from the implemented system and the money from the selling of the cassava flour and 'rapadura' produced with this electricity; the study of sensibility of the ethanol price in the electrical energy cost was done too, and the cassava flour and 'rapadura' in the family funds. From the results, it was verified that the electrical energy cost has a 16,4% impact in the family gross income and a net value around R$ 260,85/family, indicating that the community will have enough funds to pay for the energy and also will rise the amount of money for each family. Besides, the comparative analyze of the cost of the electricity from the ethanol/fuel cell reformer and photovoltaic systems shows that, considering only the maintenance and operation costs, the first one should be more attractive than the second one. (author)

  17. Mathematical Modelling of Catalytic Fixed-Bed Reactor for Carbon Dioxide Reforming of Methane over Rh/Al2O3 Catalyst

    Directory of Open Access Journals (Sweden)

    New Pei Yee

    2008-04-01

    Full Text Available A one-dimensional mathematical model was developed to simulate the performance of catalytic fixed bedreactor for carbon dioxide reforming of methane over Rh/Al2O3 catalyst at atmospheric pressure. The reactionsinvolved in the system are carbon dioxide reforming of methane (CORM and reverse water gas shiftreaction (RWGS. The profiles of CH4 and CO2 conversions, CO and H2 yields, molar flow rate and molefraction of all species as well as reactor temperature along the axial bed of catalyst were simulated. In addition,the effects of different reactor temperature on the reactor performance were also studied. The modelscan also be applied to analyze the performances of lab-scale micro reactor as well as pilot-plant scale reactorwith certain modifications and model verification with experimental data. © 2008 BCREC UNDIP. All rights reserved.[Received: 20 August 2008; Accepted: 25 September 2008][How to Cite: N.A.S. Amin, I. Istadi, N.P. Yee. (2008. Mathematical Modelling of Catalytic Fixed-Bed Reactor for Carbon Dioxide Reforming of Methane over Rh/Al2O3 Catalyst. Bulletin of Chemical Reaction Engineering and Catalysis, 3 (1-3: 21-29. doi:10.9767/bcrec.3.1-3.19.21-29

  18. Thermal design and analysis of the HTGR fuel element vertical carbonizing and annealing furnace

    International Nuclear Information System (INIS)

    Llewellyn, G.H.

    1977-06-01

    Computer analyses of the thermal design for the proposed HTGR fuel element vertical carbonizing and annealing furnace were performed to verify its capability and to determine the required power input and distribution. Although the furnace is designed for continuous operation, steady-state temperature distributions were obtained by assuming internal heat generation in the fuel elements to simulate their mass movement. The furnace thermal design, the analysis methods, and the results are discussed herein

  19. Radiant non-catalytic recuperative reformer

    Energy Technology Data Exchange (ETDEWEB)

    Khinkis, Mark J.; Kozlov, Aleksandr P.

    2017-10-31

    A radiant, non-catalytic recuperative reformer has a flue gas flow path for conducting hot exhaust gas from a thermal process and a reforming mixture flow path for conducting a reforming mixture. At least a portion of the reforming mixture flow path is positioned adjacent to the flue gas flow path to permit heat transfer from the hot exhaust gas to the reforming mixture. The reforming mixture flow path contains substantially no material commonly used as a catalyst for reforming hydrocarbon fuel (e.g., nickel oxide, platinum group elements or rhenium), but instead the reforming mixture is reformed into a higher calorific fuel via reactions due to the heat transfer and residence time. In a preferred embodiment, a portion of the reforming mixture flow path is positioned outside of flue gas flow path for a relatively large residence time.

  20. Interaction of carbon reduction and green energy promotion in a small fossil-fuel importing economy

    International Nuclear Information System (INIS)

    Pethig, Ruediger; Wittlich, Christian

    2009-01-01

    We study the incidence of carbon-reduction and green-energy promotion policies in an open fossil-fuel importing general equilibrium economy. The focus is on mixed price-based or quantity-based policies. Instruments directed toward promoting green energy are shown to reduce also carbon emissions and vice versa. Their direct effects are stronger than their side effects, the more so, the greater is the elasticity of substitution in consumption between energy and the consumption good. We calculate the effects of variations in individual policy parameters, especially on energy prices and welfare costs, and determine the impact of exogenous fossil-fuel price shocks on the economy. (orig.)

  1. Reduced carbon emission estimates from fossil fuel combustion and cement production in China

    OpenAIRE

    Liu, Zhu; Guan, Dabo; Wei, Wei; Davis, Steven J.; Ciais, Philippe; Bai, Jin; Peng, Shushi; Zhang, Qiang; Hubacek, Klaus; Garland, Gregg; Andres, Robert J.; Crawford-Brown, Douglas; Lin, Jintai; Zhao, Hongyan; Hong, Chaopeng

    2015-01-01

    This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/nature14677 Nearly three-quarters of the growth in global carbon emission from burning of fossil fuels and cement production between 2010 and 2012 occurred in China. Yet estimates of Chinese emissions remain subject to large uncertainty; inventories of China's total fossil fuel carbon emissions in 2008 varied by 0.3 GtC, or 15 per cent. The primary sources of this uncertainty are c...

  2. The potential role of alcohol fuels in reducing carbon dioxide emissions

    International Nuclear Information System (INIS)

    Duff, S.J.B.

    1991-01-01

    Atmospheric concentrations of CO 2 have increased from 280 to 350 mg/l over the past two hundred years. One of the principal causes has been the increased reliance on combustion of fossil fuels to generate energy. Higher CO 2 levels have been historically correlated with warming of the earth. While attempts have been made to quantify and model the relationships between carbon dioxide emissions, atmospheric CO 2 concentrations, and global climate changes, the state of the current knowledge base is such that large uncertainties persist. It is precisely these uncertainties which has evoked justifiable concern among the scientific community. The use of biomass fuels such as alcohols can provide a partial solution to the problem of increasing emissions of CO 2 . Combustion of biomass fuels releases carbon previously sequestered from the atmosphere during growth. There is a cycling of carbon, with net additions to the atmosphere resulting only from losses, or the use of fossil fuels for process energy. Alcohol fuels can make their biggest impact in the transportation sector, which, in industrial nations, contributes up to 32% of CO 2 emissions. While not the complete answer, alcohol fuels can make a significant impact, and will no doubt be one factor in a multidimensional approach to reducing CO 2 emissions. 17 refs., 4 figs., 10 tabs

  3. CarbonNanoTubes (CNT) in bipolar plates for PEM fuel cell applications

    Energy Technology Data Exchange (ETDEWEB)

    Grundler, M.; Derieth, T.; Beckhaus, P.; Heinzel, A. [centre for fuel cell technology ZBT GmbH (Germany)

    2010-07-01

    Using standard mass production techniques for the fabrication of fuel cell components, such as bipolar plates, is a main issue for the commercialisation of PEM fuel cell systems. Bipolar plates contribute significantly to the cost structure of PEM stacks. In an upcoming fuel cell market a large number of bipolar plates with specific high-quality standards will be needed. At the Centre for Fuel Cell Technology (ZBT) together with the University of Duisburg-Essen fuel cell stacks based on injection moulded bipolar plates have been developed and demonstrated successfully [1]. This paper focuses on the interactions between carbon filling materials (graphite, carbon black and carbon nanotubes (CNT)) in compound based bipolar plates and especially the potential of CNTs, which were used in bipolar plates for the first time. The entire value added chain based on the feedstock, the compounding and injection moulding process, the component bipolar plate, up to the operation of a PEM single fuel cell stack with CNT-based bipolar plates is disclosed. (orig.)

  4. Enhancing hybrid direct carbon fuel cell anode performance using Ag2O

    DEFF Research Database (Denmark)

    Deleebeeck, Lisa; Ippolito, Davide; Kammer Hansen, Kent

    2015-01-01

    A hybrid-direct carbon fuel cell (HDCFC), consisting of a molten slurry of solid carbon black and (Li-K)2CO3 added to the anode chamber of a solid oxide fuel cell, was characterized using current-potential-power density curves, electrochemical impedance spectroscopy, and cyclic voltammetry. Two...... types of experimental setups were employed in this study, an anode-supported full cell configuration (two electrodes, two atmospheres setup) and a 3-electrode electrolyte-supported half-cell setup (single atmosphere). Anode processes with and without catalysts were investigated as a function...... of temperature (700-800 °C) and anode sweep gas (N2, 4-100% CO2 in N2-CO2). It was shown that the addition of silver based catalysts (Ag, Ag2O, Ag2CO3) into the carbon-carbonate slurry enhanced the performance of the HDCFC....

  5. Steam reformer with catalytic combustor

    Science.gov (United States)

    Voecks, Gerald E. (Inventor)

    1990-01-01

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

  6. Low-temperature carbonization of bituminous coal for the production of solid, liquid, and gaseous fuels

    Energy Technology Data Exchange (ETDEWEB)

    1942-01-01

    Properties and uses of low-temperature coke for producing ferrosilicon, CaC/sub 2/ generator gas and water gas, as a fuel for boilers and household use and as a diluent for coking coal, and the properties and uses of low-temperature tar, gasoline, gas, and liquefied gas are described. By using a circulating gas, it is possible to obtain in low-temperature carbonization of bituminous coal a fuel oil for the navy. Aging-test data of such an oil are given. Several plants in Upper Silesia, using the Lurgi circulation process are producing a fuel oil that meets specification.

  7. Azobenzene-functionalized carbon nanotubes as high-energy density solar thermal fuels.

    Science.gov (United States)

    Kolpak, Alexie M; Grossman, Jeffrey C

    2011-08-10

    Solar thermal fuels, which reversibly store solar energy in molecular bonds, are a tantalizing prospect for clean, renewable, and transportable energy conversion/storage. However, large-scale adoption requires enhanced energy storage capacity and thermal stability. Here we present a novel solar thermal fuel, composed of azobenzene-functionalized carbon nanotubes, with the volumetric energy density of Li-ion batteries. Our work also demonstrates that the inclusion of nanoscale templates is an effective strategy for design of highly cyclable, thermally stable, and energy-dense solar thermal fuels.

  8. GSPEL - Fuel Cell Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Fuel Cell Lab (FCL)Established to investigate, integrate, testand verifyperformance and technology readiness offuel cell systems and fuel reformers for use with...

  9. Carbon Corrosion at Pt/C Interface in Proton Exchange Membrane Fuel Cell Environment

    International Nuclear Information System (INIS)

    Choi, Min Ho; Beam, Won Jin; Park, Chan Jin

    2010-01-01

    This study examined the carbon corrosion at Pt/C interface in proton exchange membrane fuel cell environment. The Pt nano particles were electrodeposited on carbon substrate, and then the corrosion behavior of the carbon electrode was examined. The carbon electrodes with Pt nano electrodeposits exhibited the higher oxidation rate and lower oxidation overpotential compared with that of the electrode without Pt. This phenomenon was more active at 75 .deg. C than 25 .deg. C. In addition, the current transients and the corresponding power spectral density (PSD) of the carbon electrodes with Pt nano electrodeposits were much higher than those of the electrode without Pt. The carbon corrosion at Pt/C interface was highly accelerated by Pt nano electrodeposits. Furthermore, the polarization and power density curves of PEMFC showed degradation in the performance due to a deterioration of cathode catalyst material and Pt dissolution

  10. An investigation into carbon nanostructured materials as catalyst support in proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Veltzé, Sune

    acid treatment on the Vapour Grown Carbon Fibers™ manufactured by Showa Denko K. K. From these fibres, twelve platinised samples were investigated, of which one was platinised by a platinum phtalocyanine impregnation method, two were platinised by the polyol method and the remaining by the Bönnemann......Polymer electrolyte fuel cells (PEFCs) are among the key research areas concerning clean cost-effective energy. Carbon nano fibres (CNF), single walled carbon nano tubes (SWCNT), multi walled carbon nano tubes (MWCNT) and other related materials are among the possible successors to standard carbon...... black support materials for low platinum containing electrocatalyst. This is partly due to their high electronic conductivity. Partly due to their high surface area needed for the dispersion of nanoparticulate metal-clusters. In addition carbon nano-structures (CNF, SWCNT, MWCNT etc.) are more durable...

  11. Investigation of altenative carbon materials for fuel-cell catalyst support

    DEFF Research Database (Denmark)

    Larsen, Mikkel Juul

    In order to ensure high utilization of the catalyst material in a polymer electrolyte membrane fuel cell (PEMFC) it is usually fixed in the form of nanoparticles on a supporting material. The catalyst is platinum or a platinum alloy, and the commonly used support is carbon black (CB). Although...... structured carbon forms such as graphitized CBs, carbon nanotubes (CNTs), and carbon nanofibres (CNFs). This thesis concerns the investigation of an array of different materials which may prospec-tively replace the conventional materials used in the catalyst. The study comprised 13 carbon samples which...... nanotubes (GMWCNTs), and graphitized carbon nanofibre (CNF), while the Pt/C samples were platinized samples of some of the CNTs and CNFs (Pt/FWCNT, Pt/GMWCNT, and Pt/CNF, respectively) as well as two commercial Pt/CB reference catalysts. Comparative analyses have been performed in order to be able to assess...

  12. The European carbon balance. Part 1: fossil fuel emissions

    NARCIS (Netherlands)

    Ciais, P.; Paris, J.D.; Marland, G.; Peylin, P.; Piao, S.L.; levin, I.; Pregger, T.; Scholz, Y.; Friedrich, R.; Rivier, L.; Houweling, S.; Schulze, E.D.

    2010-01-01

    We analyzed the magnitude, the trends and the uncertainties of fossil-fuel CO2 emissions in the European Union 25 member states (hereafter EU-25), based on emission inventories from energy-use statistics. The stability of emissions during the past decade at EU-25 scale masks decreasing trends in

  13. Activated carbon derived from chitosan as air cathode catalyst for high performance in microbial fuel cells

    Science.gov (United States)

    Liu, Yi; Zhao, Yong; Li, Kexun; Wang, Zhong; Tian, Pei; Liu, Di; Yang, Tingting; Wang, Junjie

    2018-02-01

    Chitosan with rich of nitrogen is used as carbon precursor to synthesis activated carbon through directly heating method in this study. The obtained carbon is activated by different amount of KOH at different temperatures, and then prepared as air cathodes for microbial fuel cells. Carbon sample treated with double amount of KOH at 850 °C exhibits maximum power density (1435 ± 46 mW m-2), 1.01 times improved, which ascribes to the highest total surface area, moderate micropore and mesoporous structure and the introduction of nitrogen. The electrochemical impedance spectroscopy and powder resistivity state that carbon treated with double amount of KOH at 850 °C possesses lower resistance. The other electrochemical measurements demonstrate that the best kinetic activity make the above treated sample to show the best oxygen reduction reaction activity. Besides, the degree of graphitization of samples increases with the activated temperature increasing, which is tested by Raman. According to elemental analysis and X-ray photoelectron spectroscopy, all chitosan samples are nitrogen-doped carbon, and high content nitrogen (pyridinic-N) improves the electrochemical activity of carbon treated with KOH at 850 °C. Thus, carbon materials derived from chitosan would be an optimized catalyst for oxygen reduction reaction in microbial fuel cell.

  14. The value of retrofitting carbon-saving measures into fuel poor social housing

    International Nuclear Information System (INIS)

    Jenkins, D.P.

    2010-01-01

    With current fuel poverty and carbon-saving policies continuing to miss their targets in the UK, the synergy between the two problems is investigated to highlight an approach that could be mutually beneficial. Focussing on the 550,000 fuel poor socially housed dwellings in the UK, costs of between Pounds 3.9 and Pounds 17.5 bn are estimated as the required capital investment for achieving deep-cut carbon savings (defined as at least 50%) across this section of the housing stock, with a potential total annual carbon saving of 1.7 MtCO 2 . It is assumed that such costs would be largely (or totally) state-funded, though additional private investment could clearly increase the possible carbon savings across this section of the stock. The use of these socially housed fuel poor dwellings as low-carbon exemplars is discussed, and benefits for the private housing sector are postulated. The study also focuses on the problem of installing non-cost effective measures, i.e. technologies that would not currently be encouraged by existing subsidy schemes, but which might be necessary for achieving large carbon-saving targets.

  15. The Impact of Tax Reform on New Car Purchases in Ireland

    NARCIS (Netherlands)

    Hennessy, H.; Tol, R.S.J.

    2011-01-01

    We examine the impact of recent tax reforms in Ireland on private car transport and its greenhouse gas emissions. A carbon tax was introduced on fuels, and purchase (vehicle registration) and ownership (motor) taxes were switched from engine size to potential emissions. We use a demographic model of

  16. Development and test of 2 kW natural gas reformers for high and low temperature PEM fuel cells. Project report 2; Udvikling/afproevning af 2 kW naturgasreformere for hoej- og lavtemperatur PEM-braendselsceller. Projektrapport 2

    Energy Technology Data Exchange (ETDEWEB)

    Wit, J. de [Dansk Gasteknisk Center (Denmark); Bech-Madsen, J. [IRD (Denmark); Bandur, V. [DTU (Denmark); Bartholin, N. [DPS (Denmark)

    2005-11-15

    The use of fuel cells for combined heat and power generation has advantages as regards technology and usability compared to existing CHP technology. Special characteristics for a fuel cell plant are: 1) It can be constructed in modules over a wide power range, 2) The efficiency is significantly independent of size, 3) It is noiseless, 4) A flexible coupling between power and heat production, 5) As there is no movable parts, long service check intervals can be expected, 6) Low emissions. The fuel for fuel cells is hydrogen and optimal utilization and CO{sub 2} reduction will require a 'hydrogen society'. While waiting for a 'hydrogen society' to arise, it is possible to use central or on-site reformers that convert natural gas to hydrogen. There will be some CO{sub 2} emission connected to energy use. The objective of the present project has been development and test of on-site reformers (fuel processors) for hydrogen supply to respectively high and low temperature PEM fuel cells aiming at use in single family houses. Sulphur cleaning, reformers, and lab-scale coupling with fuel cell KV units have been developed and tested during the project, as well as development and test of periphery equipment. (BA)

  17. Comparative analysis between two systems to generate electric energy for isolated community in the interior of the Amazon state: fuel cells with natural gas reformer versus diesel generation; Analise comparativa entre dois sistemas de geracao de energia eletrica para a comunidade isolada no interior do estado do Amazonas: celula a combustivel com reformador para gas natural versus gerador diesel

    Energy Technology Data Exchange (ETDEWEB)

    Araujo, Paula Duarte; Bergamini, Cristiane Peres; Camargo, Joao Carlos; Lopes, Daniel Gabriel [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Fac. de Engenharia Mecanica; Esteves, Gheisa Roberta Telles [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Nucleo de Pesquisas e Estudos Ambientais; Silva, Ennio Peres da Silva [Universidade Estadual de Campinas (UNICAMP), Campinas, SP (Brazil). Inst. de Fisica Gleb Wataghin

    2004-07-01

    Although great part of the domestic territory is already supplied with electric energy, still there are many regions where the system is precarious or nonexistent, generically called isolated communities. In the majority of the cases these communities are supplied with Diesel oil generators and the substitution of this fuel for available alternative energy in the localities has been object of study of some institutions of research spread throughout the country. Currently, the use of fuel cells has been strongly argued in the generation of electric energy associated with the local energy necessity, from the use of a regional fuel and this is due to the high efficiency of allied energy conversion to the low ambient impacts that this equipment offers. Most of the different types of fuel cells use hydrogen as a fuel to produce electricity, and it is extracted from renewable or non-renewable sources of energy. Then, the article has the objective of comparing in first analysis the energy efficiency and the cost between the two systems: the ones used currently in the great majority of the isolated communities, constituted of a Diesel engine-generator system, with Natural Gas Reformer System/ Purifier of Hydrogen/ Fuel Cell/ and to analyze if such project presents characteristics that qualifies it to get the carbon credits proposed in the Mechanism of Clean Development. (author)

  18. Transportation Energy Futures Series: Alternative Fuel Infrastructure Expansion: Costs, Resources, Production Capacity, and Retail Availability for Low-Carbon Scenarios

    Energy Technology Data Exchange (ETDEWEB)

    Melaina, W. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heath, Garvin [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sandor, Debra [National Renewable Energy Lab. (NREL), Golden, CO (United States); Steward, Darlene [National Renewable Energy Lab. (NREL), Golden, CO (United States); Vimmerstedt, Laura [National Renewable Energy Lab. (NREL), Golden, CO (United States); Warner, Ethan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Webster, Karen W. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2013-04-01

    The petroleum-based transportation fuel system is complex and highly developed, in contrast to the nascent low-petroleum, low-carbon alternative fuel system. This report examines how expansion of the low-carbon transportation fuel infrastructure could contribute to deep reductions in petroleum use and greenhouse gas (GHG) emissions across the U.S. transportation sector. Three low-carbon scenarios, each using a different combination of low-carbon fuels, were developed to explore infrastructure expansion trends consistent with a study goal of reducing transportation sector GHG emissions to 80% less than 2005 levels by 2050.These scenarios were compared to a business-as-usual (BAU) scenario and were evaluated with respect to four criteria: fuel cost estimates, resource availability, fuel production capacity expansion, and retail infrastructure expansion.

  19. The effect of fuel and chlorinated hydrocarbons on a vapor phase carbon adsorption system

    International Nuclear Information System (INIS)

    Crawford, W.J.; Cheney, J.L.; Taggart, D.B.

    1995-01-01

    A soil vapor extraction (SVE) system installed at the South Tacoma Well 12A Superfund Site was designed to recover 1,2-dichloroethylene (DCE), trichloroethylene (TCE), tetrachloroethylene (PCE), and 1,1,2,2-tetrachloroethane (1,1,2,2-TCA) from the vadose zone. The basic system consisted of twenty-two extraction wells, three centrifugal blowers, and three carbon adsorbers. The carbon adsorbers were regenerated on site by steam stripping. The mixture of steam and stripped organics was condensed and then decanted to separate the water from the organic phase. The recovered water was air stripped to remove the dissolved organics prior to discharge to the city storm sewer. The recovered organic phase was then shipped off site for thermal destruction. Previous reports described operating difficulties with the decanter, and air strippers. Sampling and analyses were performed which identified the problem as the simultaneous recovery of unexpected fuel hydrocarbons in addition to the solvents. Recovery of fuels resulted in a light phase in the decanter in addition to the water and heavy solvent phases. This required redesign of the decanter to handle the third phase. The effectiveness of desorption of the carbon beds by steam stripping gradually decreased as the remediation progressed into the second year of operation. Samples were collected from the carbon beds to evaluate the effect of the fuel and chlorinated hydrocarbons on the activated carbon. This report describes the results of these analyses. The data indicated that both 1,1,2,2-TCA and fuel hydrocarbons in the C-9 to C-24 range remained in the carbon beds after steam regeneration in sufficient quantities to require replacing the carbon

  20. Steam reforming of ethanol

    DEFF Research Database (Denmark)

    Trane-Restrup, Rasmus; Dahl, Søren; Jensen, Anker Degn

    2013-01-01

    Steam reforming (SR) of oxygenated species like bio-oil or ethanol can be used to produce hydrogen or synthesis gas from renewable resources. However, deactivation due to carbon deposition is a major challenge for these processes. In this study, different strategies to minimize carbon deposition...

  1. Solid oxide fuel cell bi-layer anode with gadolinia-doped ceria for utilization of solid carbon fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kellogg, Isaiah D. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, 290A Toomey Hall, 400 West 13th Street, Rolla, MO 65409 (United States); Department of Materials Science and Engineering, Missouri University of Science and Technology, 223 McNutt Hall, 1400 N. Bishop, Rolla, MO 65409 (United States); Koylu, Umit O. [Department of Mechanical and Aerospace Engineering, Missouri University of Science and Technology, 290A Toomey Hall, 400 West 13th Street, Rolla, MO 65409 (United States); Dogan, Fatih [Department of Materials Science and Engineering, Missouri University of Science and Technology, 223 McNutt Hall, 1400 N. Bishop, Rolla, MO 65409 (United States)

    2010-11-01

    Pyrolytic carbon was used as fuel in a solid oxide fuel cell (SOFC) with a yttria-stabilized zirconia (YSZ) electrolyte and a bi-layer anode composed of nickel oxide gadolinia-doped ceria (NiO-GDC) and NiO-YSZ. The common problems of bulk shrinkage and emergent porosity in the YSZ layer adjacent to the GDC/YSZ interface were avoided by using an interlayer of porous NiO-YSZ as a buffer anode layer between the electrolyte and the NiO-GDC primary anode. Cells were fabricated from commercially available component powders so that unconventional production methods suggested in the literature were avoided, that is, the necessity of glycine-nitrate combustion synthesis, specialty multicomponent oxide powders, sputtering, or chemical vapor deposition. The easily-fabricated cell was successfully utilized with hydrogen and propane fuels as well as carbon deposited on the anode during the cyclic operation with the propane. A cell of similar construction could be used in the exhaust stream of a diesel engine to capture and utilize soot for secondary power generation and decreased particulate pollution without the need for filter regeneration. (author)

  2. Carbon composites with metal nanoparticles for Alcohol fuel cells

    Science.gov (United States)

    Ventrapragada, Lakshman; Siddhardha, R. S.; Podilla, Ramakrishna; Muthukumar, V. S.; Creager, Stephen; Rao, A. M.; Ramamurthy, Sai Sathish

    2015-03-01

    Graphene due to its high surface area and superior conductivity has attracted wide attention from both industrial and scientific communities. We chose graphene as a substrate for metal nanoparticle deposition for fuel cell applications. There are many chemical routes for fabrication of metal-graphene composites, but they have an inherent disadvantage of low performance due to the usage of surfactants, that adsorb on their surface. Here we present a design for one pot synthesis of gold nanoparticles and simultaneous deposition on graphene with laser ablation of gold strip and functionalized graphene. In this process there are two natural advantages, the nanoparticles are synthesized without any surfactants, therefore they are pristine and subsequent impregnation on graphene is linker free. These materials are well characterized with electron microscopy to find their morphology and spectroscopic techniques like Raman, UV-Vis. for functionality. This gold nanoparticle decorated graphene composite has been tested for its electrocatalytic oxidation of alcohols for alkaline fuel cell applications. An electrode made of this composite showed good stability for more than 200 cycles of operation and reported a low onset potential of 100 mV more negative, an important factor for direct ethanol fuel cells.

  3. Distributional effects of a carbon tax on car fuels in France

    International Nuclear Information System (INIS)

    Bureau, Benjamin

    2011-01-01

    This paper analyses the distributional effects of alternative scenarios of carbon taxes on car fuels using disaggregated French panel data from 2003 to 2006. It incorporates household price responsiveness that differs across income groups into a consumer surplus measure of tax burden. Carbon taxation is regressive before revenue recycling. However, taking into account the benefits from congestion reduction induced by the tax mitigates regressivity. We show also that recycling additional revenues from the carbon tax either in equal amounts to each household or according to household size makes poorest households better off. (author)

  4. Distributional effects of a carbon tax on car fuels in France

    International Nuclear Information System (INIS)

    Bureau, B.

    2010-01-01

    This paper analyses the distributional effects of alternative scenarios of carbon taxes on car fuels using dis-aggregated French panel data from 2003 to 2006. It incorporates household price responsiveness that differs across income groups into a consumer surplus measure of tax burden. Carbon taxation is regressive before revenue recycling. However, taking into account the benefits from congestion reduction induced by the tax mitigates regressiveness. We show also that recycling additional revenues from the carbon tax either in equal amounts to each household or according to household size makes poorest households better off. (author)

  5. Combustion studies of coal derived solid fuels by thermogravimetric analysis. III. Correlation between burnout temperature and carbon combustion efficiency

    Science.gov (United States)

    Rostam-Abadi, M.; DeBarr, J.A.; Chen, W.T.

    1990-01-01

    Burning profiles of 35-53 ??m size fractions of an Illinois coal and three partially devolatilized coals prepared from the original coal were obtained using a thermogravimetric analyzer. The burning profile burnout temperatures were higher for lower volatile fuels and correlated well with carbon combustion efficiencies of the fuels when burned in a laboratory-scale laminar flow reactor. Fuels with higher burnout temperatures had lower carbon combustion efficiencies under various time-temperature conditions in the laboratory-scale reactor. ?? 1990.

  6. Electrochemical characteristics of vanadium redox reactions on porous carbon electrodes for microfluidic fuel cell applications

    International Nuclear Information System (INIS)

    Lee, Jin Wook; Hong, Jun Ki; Kjeang, Erik

    2012-01-01

    Microfluidic vanadium redox fuel cells are membraneless and catalyst-free fuel cells comprising a microfluidic channel network with two porous carbon electrodes. The anolyte and catholyte for fuel cell operation are V(II) and V(V) in sulfuric acid based aqueous solution. In the present work, the electrochemical characteristics of the vanadium redox reactions are investigated on commonly used porous carbon paper electrodes and compared to a standard solid graphite electrode as baseline. Half-cell electrochemical impedance spectroscopy is applied to measure the overall ohmic resistance and resistivity of the electrodes. Kinetic parameters for both V(II) and V(V) discharging reactions are extracted from Tafel plots and compared for the different electrodes. Cyclic voltammetry techniques reveal that the redox reactions are irreversible and that the magnitudes of peak current density vary significantly for each electrode. The obtained kinetic parameters for the carbon paper are implemented into a numerical simulation and the results show a good agreement with measured polarization curves from operation of a microfluidic vanadium redox fuel cell employing the same material as flow-through porous electrodes. Recommendations for microfluidic fuel cell design and operation are provided based on the measured trends.

  7. Highly Loaded Carbon Black Supported Pt Catalysts for Fuel Cells

    Czech Academy of Sciences Publication Activity Database

    Kaluža, Luděk; Larsen, M.J.; Zdražil, Miroslav; Gulková, Daniela; Vít, Zdeněk; Šolcová, Olga; Soukup, Karel; Koštejn, Martin; Bonde, J.L.; Maixnerová, Lucie; Odgaard, M.

    2015-01-01

    Roč. 256, NOV 1 (2015), s. 375-383 ISSN 0920-5861 R&D Projects: GA MŠk(CZ) 7HX13003 EU Projects: European Commission(XE) 303466 - IMMEDIATE Institutional support: RVO:67985858 Keywords : carbon black * fuell cell * electrocatalyst Subject RIV: CI - Industrial Chemistry , Chemical Engineering Impact factor: 4.312, year: 2015

  8. Carbon nanotubes based nafion composite membranes for fuel cell applications

    CSIR Research Space (South Africa)

    Cele, NP

    2009-01-01

    Full Text Available Carbon nanotubes (CNTs) containing Nafion composite membranes were prepared via melt-blending at 250 °C. Using three different types of CNTs such as pure CNTs (pCNTs), oxidised CNTs (oCNTs) and amine functionalised CNTs (fCNTs); the effect of CNTs...

  9. A new evaluation of the uncertainty associated with CDIAC estimates of fossil fuel carbon dioxide emission

    Directory of Open Access Journals (Sweden)

    Robert J. Andres

    2014-07-01

    Full Text Available Three uncertainty assessments associated with the global total of carbon dioxide emitted from fossil fuel use and cement production are presented. Each assessment has its own strengths and weaknesses and none give a full uncertainty assessment of the emission estimates. This approach grew out of the lack of independent measurements at the spatial and temporal scales of interest. Issues of dependent and independent data are considered as well as the temporal and spatial relationships of the data. The result is a multifaceted examination of the uncertainty associated with fossil fuel carbon dioxide emission estimates. The three assessments collectively give a range that spans from 1.0 to 13% (2 σ. Greatly simplifying the assessments give a global fossil fuel carbon dioxide uncertainty value of 8.4% (2 σ. In the largest context presented, the determination of fossil fuel emission uncertainty is important for a better understanding of the global carbon cycle and its implications for the physical, economic and political world.

  10. Fuel treatment effects on tree-based forest carbon storage and emissions under modeled wildfire scenarios

    Science.gov (United States)

    M. Hurteau; M. North

    2009-01-01

    Forests are viewed as a potential sink for carbon (C) that might otherwise contribute to climate change. It is unclear, however, how to manage forests with frequent fire regimes to maximize C storage while reducing C emissions from prescribed burns or wildfire. We modeled the effects of eight different fuel treatments on treebased C storage and release over a century,...

  11. Climate Policy and the Optimal Extraction of High- and Low-Carbon Fossil Fuels

    NARCIS (Netherlands)

    Smulders, J.A.; van der Werf, E.H.

    2005-01-01

    We study how restricting CO2 emissions affcts resource prices and depletion over time.We use a Hotelling-style model with two nonrenewable fossil fuels that differ in their carbon content (e.g. coal and natural gas) and that are imperfect substitutes in final good production.We study both an

  12. Removal of CO from reformate for PEFC application.

    Energy Technology Data Exchange (ETDEWEB)

    Lee, S. H. D.

    1998-09-14

    Polymer electrolyte fuel cells (PEFCs) are being actively developed worldwide for transportation applications. The fuel gas generated from reforming hydrocarbon fuels contains small amounts of CO (0.5-1 vol%), even after the water-gas shift reaction. Carbon monoxide is preferentially adsorbed on the platinum electrocatalyst in the PEFC, thus blocking the access of H{sub 2} to the surface of the catalyst and resulting in the degradation of the cell performance. Therefore, the CO concentration in the PBFC reformate must be reduced to a tolerable level of {le} 100 ppm (1). Catalytic preferential oxidation (2), anode air bleed (3), or a combination of the two can be used to reduce CO to trace levels, but their use in a dynamically varying system is problematic. We are developing a sorption process based on the reversible complex-forming and dissociation reactions of CO with Cu(I). These reactions are well documented in patent and literature (4,5).

  13. Solid oxide fuel cell performance comparison fuelled by methane, MeOH, EtOH and diesel surrogate C8H18

    DEFF Research Database (Denmark)

    Liso, Vincenzo; Cinti, Giovanni; Nielsen, Mads Pagh

    2016-01-01

    Carbon deposition is a major cause of degradation in solid oxide fuel cell systems. The ability to predict carbon formation in reforming processes is thus absolutely necessary for stable operation of solid oxide fuel cell systems. In the open literature it is found that thesteam input is always c...

  14. Long-term ocean oxygen depletion in response to carbon dioxide emissions from fossil fuels

    DEFF Research Database (Denmark)

    Shaffer, G.; Olsen, S.M.; Pedersen, Jens Olaf Pepke

    2009-01-01

    Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion and assoc......Ongoing global warming could persist far into the future, because natural processes require decades to hundreds of thousands of years to remove carbon dioxide from fossil-fuel burning from the atmosphere(1-3). Future warming may have large global impacts including ocean oxygen depletion...... solubility from surface-layer warming accounts for most of the enhanced oxygen depletion in the upper 500 m of the ocean. Possible weakening of ocean overturning and convection lead to further oxygen depletion, also in the deep ocean. We conclude that substantial reductions in fossil-fuel use over the next...

  15. Automobiles and global warming: Alternative fuels and other options for carbon dioxide emissions reduction

    International Nuclear Information System (INIS)

    Sagar, A.D.

    1995-01-01

    Automobiles are a source of considerable pollution at the global level, including a significant fraction of the total greenhouse gas emissions. Alternative fuels have received some attention as potential options to curtail the carbon dioxide emissions from motor vehicles. This article discusses the feasibility and desirability (from a technical as well as a broader environmental perspective) of the large-scale production and use of alternative fuels as a strategy to mitigate automotive carbon dioxide emissions. Other options such as improving vehicle efficiency and switching to more efficient modes of passenger transportation are also discussed. These latter options offer an effective and immediate way to tackle the greenhouse and other pollutant emission from automobiles, especially as the limitations of currently available alternative fuels and the technological and other constraints for potential future alternatives are revealed

  16. Combined steam and carbon dioxide reforming of methane and side reactions: Thermodynamic equilibrium analysis and experimental application

    International Nuclear Information System (INIS)

    Jang, Won-Jun; Jeong, Dae-Woon; Shim, Jae-Oh; Kim, Hak-Min; Roh, Hyun-Seog; Son, In Hyuk; Lee, Seung Jae

    2016-01-01

    Highlights: • Selected variables have a significant influence on yields of synthesis gas. • (CO_2 + H_2O)/CH_4 affects the temperature which can achieve the maximum conversion. • Coke is formed at low temperatures even with excess oxidizing agent. • The occurrence of RWGS becomes critical in real chemical reactions. • Equilibrium conversions are maintained for 500 h without detectable deactivation. - Abstract: Thermodynamic equilibrium analysis of the combined steam and carbon dioxide reforming of methane (CSCRM) and side reactions was performed using total Gibbs free energy minimization. The effects of (CO_2 + H_2O)/CH_4 ratio (0.9–2.9), CO_2:H_2O ratio (3:1–1:3), and temperature (500–1000 °C) on the equilibrium conversions, yields, coke yield, and H_2/CO ratio were investigated. A (CO_2 + H_2O)/CH_4 ratio greater than 1.2, a CO_2:H_2O ratio of 1:2.1, and a temperature of at least 850 °C are preferable reaction conditions for the synthesis gas preparation in the gas to liquid process. Simulated conditions were applied to the CSCRM reaction and the experimental data were compared with the thermodynamic equilibrium results. The thermodynamic equilibrium results were mostly consistent with the experimental data, but the reverse water gas shift reaction rapidly occurred in the real chemical reaction and under excess oxidizing agent conditions. In addition, a long-term stability test (under simulated conditions) showed that the equilibrium conversion was maintained for 500 h and that the coke formation on the used catalyst was not observed.

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

    Science.gov (United States)

    Jablonski, Whitney S.

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

  18. Study of a molten carbonate fuel cell combined heat, hydrogen and power system: Energy analysis

    International Nuclear Information System (INIS)

    Agll, Abdulhakim Amer A.; Hamad, Yousif M.; Hamad, Tarek A.; Thomas, Mathew; Bapat, Sushrut; Martin, Kevin B.; Sheffield, John W.

    2013-01-01

    Countries around the world are trying to use alternative fuels and renewable energy to reduce the energy consumption and greenhouse gas emissions. Biogas contains methane is considered a potential source of clean renewable energy. This paper discusses the design of a combined heat, hydrogen and power system, which generated by methane with use of Fuelcell, for the campus of Missouri University of Science and Technology located in Rolla, Missouri, USA. An energy flow and resource availability study was performed to identify sustainable type and source of feedstock needed to run the Fuelcell at its maximum capacity. FuelCell Energy's DFC1500 unit (a molten carbonate Fuelcell) was selected as the Fuelcell for the tri-generation (heat, hydrogen and electric power) system. This tri-generation system provides electric power to the campus, thermal energy for heating the anaerobic digester, and hydrogen for transportation, backup power and other applications on the campus. In conclusion, the combined heat, hydrogen and power system reduces fossil fuel usage, and greenhouse gas emissions at the university campus. -- Highlights: • Combined heat, hydrogen and power (CHHP) using a molten carbonate fuel cell. • Energy saving and alternative fuel of the products are determined. • Energy saving is increased when CHHP technology is implemented. • CHHP system reduces the greenhouse gas emissions and fuel consumption

  19. Exergy analysis and optimisation of a marine molten carbonate fuel cell system in simple and combined cycle configuration

    International Nuclear Information System (INIS)

    Dimopoulos, George G.; Stefanatos, Iason C.; Kakalis, Nikolaos M.P.

    2016-01-01

    Highlights: • Process modelling and optimisation of an integrated marine MCFC system. • Component-level and spatially distributed exergy analysis and balances. • Optimal simple cycle MCFC system with 45.5% overall exergy efficiency. • Optimal combined cycle MCFC system with 60% overall exergy efficiency. • Combined cycle MCFC system yields 30% CO_2 relative emissions reduction. - Abstract: In this paper we present the exergy analysis and design optimisation of an integrated molten carbonate fuel cell (MCFC) system for marine applications, considering waste heat recovery options for additional power production. High temperature fuel cells are attractive solutions for marine energy systems, as they can significantly reduce gaseous emissions, increase efficiency and facilitate the introduction of more environmentally-friendly fuels, like LNG and biofuels. We consider an already installed MCFC system onboard a sea-going vessel, which has many tightly integrated sub-systems and components: fuel delivery and pre-reforming, internal reforming sections, electrochemical conversion, catalytic burner, air supply and high temperature exhaust gas. The high temperature exhaust gasses offer significant potential for heat recovery that can be directed into both covering the system’s auxiliary heat requirements and power production. Therefore, an integrated systems approach is employed to accurately identify the true sources of losses in the various components and to optimise the overall system with respect to its energy efficiency, taking into account the various trade-offs and subject to several constraints. Here, we present a four-step approach: a. dynamic process models development of simple and combined-cycle MCFC system; b. MCFC components and system models calibration via onboard MCFC measurements; c. exergy analysis, and d. optimisation of the simple and combined-cycle systems with respect to their exergetic performance. Our methodology is based on the

  20. Graphitic Carbon Nitride as a Catalyst Support in Fuel Cells and Electrolyzers

    International Nuclear Information System (INIS)

    Mansor, Noramalina; Miller, Thomas S.; Dedigama, Ishanka; Jorge, Ana Belen; Jia, Jingjing; Brázdová, Veronika; Mattevi, Cecilia; Gibbs, Chris; Hodgson, David; Shearing, Paul R.; Howard, Christopher A.; Corà, Furio; Shaffer, Milo; Brett, Daniel J.L.

    2016-01-01

    Highlights: • Graphitic carbon nitride (gCN) describes many materials with different structures. • gCNs can exhibit excellent mechanical, chemical and thermal resistance. • A major obstacle for pure gCN catalyst supports is limited electronic conductivity. • Composite/Hybrid gCN structures show excellent performance as catalyst supports. • gCNs have great potential for use in fuel calls and water electrolyzers. - Abstract: Electrochemical power sources, such as polymer electrolyte membrane fuel cells (PEMFCs), require the use of precious metal catalysts which are deposited as nanoparticles onto supports in order to minimize their mass loading and therefore cost. State-of-the-art/commercial supports are based on forms of carbon black. However, carbon supports present disadvantages including corrosion in the operating fuel cell environment and loss of catalyst activity. Here we review recent work examining the potential of different varieties of graphitic carbon nitride (gCN) as catalyst supports, highlighting their likely benefits, as well as the challenges associated with their implementation. The performance of gCN and hybrid gCN-carbon materials as PEMFC electrodes is discussed, as well as their potential for use in alkaline systems and water electrolyzers. We illustrate the discussion with examples taken from our own recent studies.

  1. Immobilization of carbon 14 contained in spent fuel hulls through melting-solidification treatment

    International Nuclear Information System (INIS)

    Mizuno, T.; Maeda, T.; Nakayama, S.; Banba, T.

    2004-01-01

    The melting-solidification treatment of spent nuclear fuel hulls is a potential technique to improve immobilization/stabilization of carbon-14 which is mobile in the environment due to its weakly absorbing properties. Carbon-14 can be immobilized in a solid during the treatment under an inert gas atmosphere, where carbon is not oxidized to gaseous form and remains in the solid. A series of laboratory scale experiments on retention of carbon into an alloy waste form was conducted. Metallic zirconium was melted with metallic copper (Zr/Cu=8/2 in weight) at 1200 deg C under an argon atmosphere. Almost all of the carbon remained in the resulting zirconium-copper alloy. (authors)

  2. Climate policy and the optimal extraction of high- and low-carbon fossil fuels

    International Nuclear Information System (INIS)

    Smulders, S.; Van der Werf, E.

    2005-01-01

    We study how restricting CO2 emissions affects resource prices and depletion over time. We use a Hotelling-style model with two non- renewable fossil fuels that differ in their carbon content (e.g. coal and natural gas) and that are imperfect substitutes in final good production. We study both an unexpected constraint and an anticipated constraint. Both shocks induce intertemporal substitution of resource use. When emissions are unexpectedly restricted, it is cost-effective to use high-carbon resources relatively more (less) intensively on impact if this resource is relatively scarce (abundant). If the emission constraint is anticipated, it is cost-effective to use relatively more (less) of the low-carbon input before the constraint becomes binding, in order to conserve relatively more (less) of the high-carbon input for the period when climate policy is active in case the high-carbon resource is relatively scarce (abundant)

  3. High-temperature reactors for underground liquid-fuels production with direct carbon sequestration

    International Nuclear Information System (INIS)

    Forsberg, C. W.

    2008-01-01

    The world faces two major challenges: (1) reducing dependence on oil from unstable parts of the world and (2) minimizing greenhouse gas emissions. Oil provides 39% of the energy needs of the United States, and oil refineries consume over 7% of the total energy. The world is running out of light crude oil and is increasingly using heavier fossil feedstocks such as heavy oils, tar sands, oil shale, and coal for the production of liquid fuels (gasoline, diesel, and jet fuel). With heavier feedstocks, more energy is needed to convert the feedstocks into liquid fuels. In the extreme case of coal liquefaction, the energy consumed in the liquefaction process is almost twice the energy value of the liquid fuel. This trend implies large increases in carbon dioxide releases per liter of liquid transport fuel that is produced. It is proposed that high-temperature nuclear heat be used to refine hydrocarbon feedstocks (heavy oil, tar sands, oil shale, and coal) 'in situ ', i.e., underground. Using these resources for liquid fuel production would potentially enable the United States to become an exporter of oil while sequestering carbon from the refining process underground as carbon. This option has become potentially viable because of three technical developments: precision drilling, underground isolation of geological formations with freeze walls, and the understanding that the slow heating of heavy hydrocarbons (versus fast heating) increases the yield of light oils while producing a high-carbon solid residue. Required peak reactor temperatures are near 700 deg. C-temperatures within the current capabilities of high-temperature reactors. (authors)

  4. Fabrication of a Flexible Micro CO Sensor for Micro Reformer Applications

    Directory of Open Access Journals (Sweden)

    Yi-Man Lo

    2010-11-01

    Full Text Available Integration of a reformer and a proton exchange membrane fuel cell (PEMFC is problematic due to the presence in the gas from the reforming process of a slight amount of carbon monoxide. Carbon monoxide poisons the catalyst of the proton exchange membrane fuel cell subsequently degrading the fuel cell performance, and necessitating the sublimation of the reaction gas before supplying to fuel cells. Based on the use of micro-electro-mechanical systems (MEMS technology to manufacture flexible micro CO sensors, this study elucidates the relation between a micro CO sensor and different SnO2 thin film thicknesses. Experimental results indicate that the sensitivity increases at temperatures ranging from 100–300 °C. Additionally, the best sensitivity is obtained at a specific temperature. For instance, the best sensitivity of SnO2 thin film thickness of 100 nm at 300 °C is 59.3%. Moreover, a flexible micro CO sensor is embedded into a micro reformer to determine the CO concentration in each part of a micro reformer in the future, demonstrating the inner reaction of a micro reformer in depth and immediate detection.

  5. Limits to the potential of bio-fuels and bio-sequestration of carbon

    International Nuclear Information System (INIS)

    Pearman, Graeme I.

    2013-01-01

    This document examines bio-physical limits of bio-fuels and bio-sequestration of carbon by examining available solar radiation and observed efficiencies with which natural ecosystems and agricultural systems convert that energy to biomass. It compares these energy/carbon exchanges with national levels of energy use and carbon emissions for Australia, Brazil, China, Japan, Republic of Korea, New Zealand, Papua New Guinea, Singapore, Sweden, United Kingdom and United States. Globally primary energy consumption (related carbon emissions) is currently equivalent to ∼0.06% of the incident solar energy, and 43% of the energy (carbon) captured by photosynthesis. The nations fall into three categories. Those with primary energy consumption that is: 1–10% (Japan, Korea and Singapore); ∼0.1% (China, UK and the US) and; 0.1–0.01% (Australia, Brazil, Papua New Guinea, New Zealand and Sweden) of incident solar radiation. The percentage of energy captured in biomass follows this pattern, but generally lower by ∼3 orders of magnitude. The energy content of traded wheat, corn and rice represents conversion efficiencies of solar radiation of 0.08–0.17% and for sugar close to 1%, ignoring energy use in production and conversion of biomass to fuels. The study implies that bio-fuels or bio-sequestration can only be a small part of an inclusive portfolio of actions towards a low carbon future and minimised net emissions of carbon to the atmosphere. - Highlights: • Global energy consumption is ∼0.06% of solar; 43% of net primary production. • 11 nations studied fall into 3 groups: consumption/solar=1–10%; ∼0.1%; 0.1–0.01%. • % of energy captured in biomass is lower by ∼3 orders of magnitude. • Crops and natural ecosystems capture 0.1–0.3% and sugar 1% of solar energy. • Significant bio-energy/carbon sequestration via biomass is unrealistic

  6. Palladium and palladium-tin supported on multi wall carbon nanotubes or carbon for alkaline direct ethanol fuel cell

    Science.gov (United States)

    Geraldes, Adriana Napoleão; Furtunato da Silva, Dionisio; Martins da Silva, Júlio César; Antonio de Sá, Osvaldo; Spinacé, Estevam Vitório; Neto, Almir Oliveira; Coelho dos Santos, Mauro

    2015-02-01

    Pd and PdSn (Pd:Sn atomic ratios of 90:10), supported on Multi Wall Carbon Nanotubes (MWCNT) or Carbon (C), are prepared by an electron beam irradiation reduction method. The obtained materials are characterized by X-Ray diffraction (XRD), Energy dispersive X-ray analysis (EDX), Transmission electron Microscopy (TEM) and Cyclic Voltammetry (CV). The activity for ethanol electro-oxidation is tested in alkaline medium, at room temperature, using Cyclic Voltammetry and Chronoamperometry (CA) and in a single alkaline direct ethanol fuel cell (ADEFC), in the temperature range of 60-90 °C. CV analysis finds that Pd/MWCNT and PdSn/MWCNT presents onset potentials changing to negative values and high current values, compared to Pd/C and PdSn/C electrocatalysts. ATR-FTIR analysis, performed during the CV, identifies acetate and acetaldehyde as principal products formed during the ethanol electro-oxidation, with low conversion to CO2. In single fuel cell tests, at 85 °C, using 2.0 mol L-1 ethanol in 2.0 mol L-1 KOH solutions, the electrocatalysts supported on MWCNT, also, show higher power densities, compared to the materials supported on carbon: PdSn/MWCNT, presents the best result (36 mW cm-2). The results show that the use of MWCNT, instead of carbon, as support, plus the addition of small amounts of Sn to Pd, improves the electrocatalytic activity for Ethanol Oxidation Reaction (EOR).

  7. Simultaneous carbonation and sulfation of CaO in Oxy-Fuel CFB combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C. [School of Energy and Power Engineering, North China Electric Power University, Baoding City, Hebei Province (China); Jia, L.; Tan, Y. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario, K1A 1M1 (Canada)

    2011-10-15

    For anthracites and petroleum cokes, the typical combustion temperature in a circulating fluidized bed (CFB) is > 900 C. At CO{sub 2} concentrations of 80-85 % (typical of oxy-fuel CFBC conditions), limestone still calcines. When the ash which includes unreacted CaO cools to the calcination temperature, carbonation of fly ash deposited on cool surfaces may occur. At the same time, indirect and direct sulfation of limestone also will occur, possibly leading to more deposition. In this study, CaO was carbonated and sulfated simultaneously in a thermogravimetric analyzer (TGA) under conditions expected in an oxy-fuel CFBC. It was found that temperature, and concentrations of CO{sub 2}, SO{sub 2}, and especially H{sub 2}O are important factors in determining the carbonation/sulfation reactions of CaO. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  8. Influence of Ce-precursor and fuel on structure and catalytic activity of combustion synthesized Ni/CeO{sub 2} catalysts for biogas oxidative steam reforming

    Energy Technology Data Exchange (ETDEWEB)

    Vita, Antonio, E-mail: antonio.vita@itae.cnr.it; Italiano, Cristina; Fabiano, Concetto; Laganà, Massimo; Pino, Lidia

    2015-08-01

    A series of nanosized Ni/CeO{sub 2} catalysts were prepared by Solution Combustion Synthesis (SCS) varying the fuel (oxalyldihydrazide, urea, carbohydrazide and glycerol), the cerium precursor (cerium nitrate and cerium ammonium nitrate) and the nickel loading (ranging between 3.1 and 15.6 wt%). The obtained powders were characterized by X-ray Diffraction (XRD), N{sub 2}-physisorption, CO-chemisorption, Temperature Programmed Reduction (H{sub 2}-TPR) and Scanning Electron Microscopy (SEM). The catalytic activity towards the Oxy Steam Reforming (OSR) of biogas was assessed. The selected operating variables have a strong influence on the nature of combustion and, in turn, on the morphological and structural properties of the synthesized catalysts. Particularly, the use of urea allows to improve nickel dispersion, surface area, particle size and reducibility of the catalysts, affecting positively the biogas OSR performances. - Highlights: • Synthesis of Ni/CeO{sub 2} nanopowders by quick and easy solution combustion synthesis. • The fuel and precursor drive the structural and morphological properties of the catalysts. • The use of urea as fuel allows to improve nickel dispersion, surface area and particle size. • Ni/CeO{sub 2} (7.8 wt% of Ni loading) powders synthesized by urea route exhibits high performances for the biogas OSR process.

  9. Influence of Ce-precursor and fuel on structure and catalytic activity of combustion synthesized Ni/CeO2 catalysts for biogas oxidative steam reforming

    International Nuclear Information System (INIS)

    Vita, Antonio; Italiano, Cristina; Fabiano, Concetto; Laganà, Massimo; Pino, Lidia

    2015-01-01

    A series of nanosized Ni/CeO 2 catalysts were prepared by Solution Combustion Synthesis (SCS) varying the fuel (oxalyldihydrazide, urea, carbohydrazide and glycerol), the cerium precursor (cerium nitrate and cerium ammonium nitrate) and the nickel loading (ranging between 3.1 and 15.6 wt%). The obtained powders were characterized by X-ray Diffraction (XRD), N 2 -physisorption, CO-chemisorption, Temperature Programmed Reduction (H 2 -TPR) and Scanning Electron Microscopy (SEM). The catalytic activity towards the Oxy Steam Reforming (OSR) of biogas was assessed. The selected operating variables have a strong influence on the nature of combustion and, in turn, on the morphological and structural properties of the synthesized catalysts. Particularly, the use of urea allows to improve nickel dispersion, surface area, particle size and reducibility of the catalysts, affecting positively the biogas OSR performances. - Highlights: • Synthesis of Ni/CeO 2 nanopowders by quick and easy solution combustion synthesis. • The fuel and precursor drive the structural and morphological properties of the catalysts. • The use of urea as fuel allows to improve nickel dispersion, surface area and particle size. • Ni/CeO 2 (7.8 wt% of Ni loading) powders synthesized by urea route exhibits high performances for the biogas OSR process

  10. Synthesis and Activity Test of Cu/ZnO/Al2O3 for the Methanol Steam Reforming as a Fuel Cell’s Hydrogen Supplier

    Directory of Open Access Journals (Sweden)

    IGBN Makertihartha

    2009-05-01

    Full Text Available The synthesis of hydrogen from hydrocarbons through the steam reforming of methanol on Cu/ZnO/Al2O3 catalyst has been investigated. This process is assigned to be one of the promising alternatives for fuel cell hydrogen process source. Hydrogen synthesis from methanol can be carried out by means of methanol steam reforming which is a gas phase catalytic reaction between methanol and water. In this research, the Cu/ZnO/Al2O3 catalyst prepared by the dry impregnation was used. The specific surface area of catalyst was 194.69 m2/gram.The methanol steam reforming (SRM reaction was carried out by means of the injection of gas mixture containing methanol and water with 1:1.2 mol ratio and 20-90 mL/minute feed flow rate to a fixed bed reactor loaded by 1 g of catalyst. The reaction temperature was 200-300 °C, and the reactor pressure was 1 atm. Preceding the reaction, catalyst was reduced in the H2/N2 mixture at 160 °C. This study shows that at 300 °C reaction temperature, methanol conversion reached 100% at 28 mL/minute gas flow rate. This conversion decreased significantly with the increase of gas flow rate. Meanwhile, the catalyst prepared for SRM was stable in 36 hours of operation at 260 °C. The catalyst exhibited a good stability although the reaction condition was shifted to a higher gas flow rate.

  11. Control structure design of a solid oxide fuel cell and a molten carbonate fuel cell integrated system: Top-down analysis

    International Nuclear Information System (INIS)

    Jienkulsawad, Prathak; Skogestad, Sigurd; Arpornwichanop, Amornchai

    2017-01-01

    Highlights: • Control structure of the combined fuel cell system is designed. • The design target is trade-off between power generation and carbon dioxide emission. • Constraints are considered according to fuel cell safe operation. • Eight variables have to be controlled to maximize profit. • Two control structures are purposed for three active constraint regions. - Abstract: The integrated system of a solid oxide fuel cell and molten carbonate fuel cell theoretically has very good potential for power generation with carbon dioxide utilization. However, the control strategy of such a system needs to be considered for efficient operation. In this paper, a control structure design for an integrated fuel cell system is performed based on economic optimization to select manipulated variables, controlled variables and control configurations. The objective (cost) function includes a carbon tax to get an optimal trade-off between power generation and carbon dioxide emission, and constraints include safe operation. This study focuses on the top-down economic analysis which is the first part of the design procedure. Three actively constrained regions as a function of the main disturbances, namely, the fuel and steam feed rates, are identified; each region represents different sets of active constraints. Under nominal operating conditions, the system operates in region I. However, operating the fuel cell system in region I and II can use the same structure, but in region III, a different control structure is required.

  12. Carbon Dioxide Dry Reforming of Glycerol for Hydrogen Production using Ni/ZrO2 and Ni/CaO as Catalysts

    Directory of Open Access Journals (Sweden)

    Nur Nabillah Mohd Arif

    2016-08-01

    Full Text Available Glycerol, byproduct from the biodiesel production can be effectively utilized as the promising source of synthesis gas (syngas through a dry reforming reaction. Combination of these waste materials with greenhouse gases which is carbon dioxide (CO2 will help to reduce environmental problem such as global warming. This dry reforming reaction has been carried out in a fixed bed batch reactor at 700 °C under the atmospheric pressure for 3 hours. In this experiment, reforming reaction was carried out using Nickel (Ni as based catalyst and supported with zirconium (ZrO2 and calcium (CaO oxides. The catalysts were prepared by wet impregnation method and characterized using Bruanaer-Emmett-Teller (BET surface area, Scanning Electron Microscopy (SEM, X-ray Diffraction (XRD, Thermo Gravimetric (TGA, and Temperature Programmed Reduction (TPR analysis. Reaction studies show that 15% Ni/CaO give the highest hydrogen yield and glycerol conversion that peaked at 24.59% and 30.32%, respectively. This result is verified by XRD analysis where this catalyst shows low crystallinity and fine dispersion of Ni species resulted in high specific surface area which gives 44.93 m2/g that is validated by BET.  Copyright © 2016 BCREC GROUP. All rights reserved Received: 21st January 2016; Revised: 24th February 2016; Accepted: 29th February 2016 How to Cite: Arif, N.M.M., Vo, D.V.N., Azizan,M.T., Abidin S.Z. (2016. Carbon Dioxide Dry Reforming of Glycerol for Hydrogen Production using Ni/ZrO2 and Ni/CaO as Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 200-209 (doi:10.9767/bcrec.11.2.551.200-209 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.551.200-209

  13. Single wall carbon nanotube supports for portable direct methanol fuel cells.

    Science.gov (United States)

    Girishkumar, G; Hall, Timothy D; Vinodgopal, K; Kamat, Prashant V

    2006-01-12

    Single-wall and multiwall carbon nanotubes are employed as carbon supports in direct methanol fuel cells (DMFC). The morphology and electrochemical activity of single-wall and multiwall carbon nanotubes obtained from different sources have been examined to probe the influence of carbon support on the overall performance of DMFC. The improved activity of the Pt-Ru catalyst dispersed on carbon nanotubes toward methanol oxidation is reflected as a shift in the onset potential and a lower charge transfer resistance at the electrode/electrolyte interface. The evaluation of carbon supports in a passive air breathing DMFC indicates that the observed power density depends on the nature and source of carbon nanostructures. The intrinsic property of the nanotubes, dispersion of the electrocatalyst and the electrochemically active surface area collectively influence the performance of the membrane electrode assembly (MEA). As compared to the commercial carbon black support, single wall carbon nanotubes when employed as the support for anchoring the electrocatalyst particles in the anode and cathode sides of MEA exhibited a approximately 30% enhancement in the power density of a single stack DMFC operating at 70 degrees C.

  14. 40 CFR 600.510-12 - Calculation of average fuel economy and average carbon-related exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... and average carbon-related exhaust emissions. 600.510-12 Section 600.510-12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) ENERGY POLICY FUEL ECONOMY AND CARBON-RELATED EXHAUST EMISSIONS OF... Transportation. (iv) [Reserved] (2) Average carbon-related exhaust emissions will be calculated to the nearest...

  15. Climate Change Effects of Forest Management and Substitution of Carbon-Intensive Materials and Fossil Fuels

    Science.gov (United States)

    Sathre, R.; Gustavsson, L.; Haus, S.; Lundblad, M.; Lundström, A.; Ortiz, C.; Truong, N.; Wikberg, P. E.

    2016-12-01

    Forests can play several roles in climate change mitigation strategies, for example as a reservoir for storing carbon and as a source of renewable materials and energy. To better understand the linkages and possible trade-offs between different forest management strategies, we conduct an integrated analysis where both sequestration of carbon in growing forests and the effects of substituting carbon intensive products within society are considered. We estimate the climate effects of directing forest management in Sweden towards increased carbon storage in forests, with more land set-aside for protection, or towards increased forest production for the substitution of carbon-intensive materials and fossil fuels, relative to a reference case of current forest management. We develop various scenarios of forest management and biomass use to estimate the carbon balances of the forest systems, including ecological and technological components, and their impacts on the climate in terms of cumulative radiative forcing over a 100-year period. For the reference case of current forest management, increasing the harvest of forest residues is found to give increased climate benefits. A scenario with increased set-aside area and the current level of forest residue harvest begins with climate benefits compared to the reference scenario, but the benefits cannot be sustained for 100 years because the rate of carbon storage in set-aside forests diminishes over time as the forests mature, but the demand for products and fuels remains. The most climatically beneficial scenario, expressed as reduced cumulative radiative forcing, in both the short and long terms is a strategy aimed at high forest production, high residue recovery rate, and high efficiency utilization of harvested biomass. Active forest management with high harvest level and efficient forest product utilization will provide more climate benefit, compared to reducing harvest and storing more