Direct Push Groundwater Circulation Wells for Remediation of BTEX and Volatile Organics (open access)

Direct Push Groundwater Circulation Wells for Remediation of BTEX and Volatile Organics

Direct push groundwater circulation wells (DP-GCW) are a promising technology for remediation of groundwater contaminated with dissolved hydrocarbons and chlorinated solvents. In these wells, groundwater is withdrawn from the formation at the bottom of the well, aerated and vapor stripped and injected back into the formation at or above the water table. Previous field studies have shown that: (a) GCWs can circulate significant volumes of groundwater; and (b) GCWs can effectively remove volatile compounds and add oxygen. In this work, we describe the development and field-testing of a system of DP-GCWs for remediation of volatile organics such as benzene, toluene, ethylbenzene, and toluene (BTEX). The GCWs were constructed with No. 20 slotted well screen (2.4 cm ID) and natural sand pack extending from 1.5 to 8.2 m below grade. Air is introduced {approximately}7.5 m below grade via 0.6 cm tubing. Approximately 15% of the vertical length of the air supply tubing is wrapped in tangled mesh polypropylene geonet drainage fabric to provide surface area for biological growth and precipitation of oxidized iron. These materials were selected to allow rapid installation of the GCWs using 3.8 cm direct push Geoprobe{reg_sign} rods, greatly reducing well installation costs. Laboratory testing of these sparged …
Date: September 30, 2000
Creator: Borden, R. C. & Cherry, R. S.
Object Type: Report
System: The UNT Digital Library
Fuel Cell and Reversible Fuel Cell Modules for Grid-Independent Electric Power Systems (open access)

Fuel Cell and Reversible Fuel Cell Modules for Grid-Independent Electric Power Systems

None
Date: September 30, 2000
Creator: Ruhl, R. C.
Object Type: Report
System: The UNT Digital Library
Toxicity Data to Determine Refrigerant Concentration Limits (open access)

Toxicity Data to Determine Refrigerant Concentration Limits

This report reviews toxicity data, identifies sources for them, and presents resulting exposure limits for refrigerants for consideration by qualified parties in developing safety guides, standards, codes, and regulations. It outlines a method to calculate an acute toxicity exposure limit (ATEL) and from it a recommended refrigerant concentration limit (RCL) for emergency exposures. The report focuses on acute toxicity with particular attention to lethality, cardiac sensitization, anesthetic and central nervous system effects, and other escape-impairing effects. It addresses R-11, R-12, R-22, R-23, R-113, R-114, R-116, R-123, R-124, R-125, R-134, R-134a, R-E134, R-141b, R-142b, R-143a, R-152a, R-218, R-227ea, R-236fa, R-245ca, R-245fa, R-290, R-500, R-502, R-600a, R-717, and R-744. It summarizes additional data for R-14, R-115, R-170 (ethane), R-C318, R-600 (n-butane), and R-1270 (propylene) to enable calculation of limits for blends incorporating them. The report summarizes the data a nd related safety information, including classifications and flammability data. It also presents a series of tables with proposed ATEL and RCL concentrations-in dimensionless form and the latter also in both metric (SI) and inch-pound (IP) units of measure-for both the cited refrigerants and 66 zerotropic and azeotropic blends. They include common refrigerants, such as R-404A, R-407C, R-410A, and R-507A, as well as others …
Date: September 30, 2000
Creator: Calm, James M.
Object Type: Report
System: The UNT Digital Library
Noble Metals and Spinel Settling in High Level Waste Glass Melters (open access)

Noble Metals and Spinel Settling in High Level Waste Glass Melters

In the continuing effort to support the Defense Waste Processing Facility (DWPF), the noble metals issue is addressed. There is an additional concern about the amount of noble metals expected to be present in the future batches that will be considered for vitrification in the DWPF. Several laboratory, as well as melter-scale, studies have been completed by various organizations (mainly PNNL, SRTC, and WVDP in the USA). This letter report statuses the noble metals issue and focuses at the settling of noble metals in melters.
Date: September 30, 2000
Creator: Sundaram, S Kamakshi & Perez Jr, Joseph M
Object Type: Report
System: The UNT Digital Library
The power to insure: Reducing insurance claims with new electricity options (open access)

The power to insure: Reducing insurance claims with new electricity options

The benefits to the insurance industry of distributed generation technologies, especially those that use clean energy generating sources, are reviewed.
Date: September 30, 2000
Creator: Gordes, Joel N.
Object Type: Report
System: The UNT Digital Library
Materials development and field demonstration of high-recycled-content concrete for energy-efficient building construction (open access)

Materials development and field demonstration of high-recycled-content concrete for energy-efficient building construction

The project developed high-recycled-content concrete material with balanced structural and thermal attributes for use in energy-efficient building construction. Recycled plastics, tire, wool, steel and concrete were used as replacement for coarse aggregates in concrete and masonry production. With recycled materials the specific heat and thermal conductivity of concrete could be tailored to enhance the energy-efficiency of concrete buildings. A comprehensive field project was implemented which confirmed the benefits of high-recycled-content concrete for energy-efficient building construction.
Date: September 30, 2000
Creator: Ostowari, Ken & Nosson, Ali
Object Type: Report
System: The UNT Digital Library
Low NOx Burner Development Program - Final Report - 09/15/1996 - 09/30/2000 (open access)

Low NOx Burner Development Program - Final Report - 09/15/1996 - 09/30/2000

This report describes the work performed to develop and demonstrate the VISTA combustor. The development effort was planned for three phases. Laboratory testing at a 1.5 and 6 MMBtu/hr scale was performed at thermo Power Corporation during the first phase. Also during the first phase, analytic modeling was performed to guide the design modifications evaluated in the experimental testing. Toward the end of the first phase, John Zink Company entered the program to participate in the design, evaluation, testing, and demonstration of a 30 MMBtu/hr combustor. The results of the second phase testing were to be used in the demonstration of the 30 MMBtu/hr combustor in a Koch Industries boiler. The program proceeded into the second phase. Two models of the VISTA combustor were tested. Measurements of the first stage NOx production were in the range anticipated to achieve the program goals, based on analytical modeling results. While testing the VISTA combustor at the John Zink facility, John Zink elected to discontinue the development of the VISTA combustor in favor of an alternative in-house concept. As a result, this program was terminated.
Date: September 30, 2000
Creator: McClaine, Andrew W.
Object Type: Report
System: The UNT Digital Library
VALIDATION OF MERCURY CEMS WHEN COFIRING BIOMASS AT MADISON ELECTRIC'S BLOUNT STATION (open access)

VALIDATION OF MERCURY CEMS WHEN COFIRING BIOMASS AT MADISON ELECTRIC'S BLOUNT STATION

The state of Wisconsin has been concerned about mercury deposition into its lakes and streams and has been evaluating strategies to reduce mercury emissions. As part of this effort, the Blount Station, owned and operated by Madison Gas and Electric Company (MGE), has undergone a project to evaluate the effects and potential mercury emissions reduction of cofiring preconsumer waste. MGE owns and operates the Blount Generating Station located in central Madison, Wisconsin. At present, Blount operates with nine boilers and six turbine generators. The two largest boilers at Blount produce 400,000 pounds of steam per hour at 950 F and 1250 psi. These larger boilers, MGE's Boiler Nos. 8 and 9, have the capability of cofiring both paper and plastic. MGE's Blount Generating Station was one of the first electric generating stations in the United States to retrofit its existing steam boilers to successfully burn refuse-derived fuel and other alternate fuels including waste paper and wood. It is the No. 9 boiler that was the focus of this project to determine the effect of cofiring PDF (plastic- and paper-derived fuel) on speciated mercury emissions. The project was laid out to compare four different fuel combinations: (1) coal feed only, (2) …
Date: September 30, 2000
Creator: Laudal, Dennis L. & Thompson, Jeffrey S.
Object Type: Report
System: The UNT Digital Library
OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING (open access)

OPTIMIZATION OF THE CATHODE LONG-TERM STABILITY IN MOLTEN CARBONATE FUEL CELLS: EXPERIMENTAL STUDY AND MATHEMATICAL MODELING

The dissolution of NiO cathodes during cell operation is a limiting factor to the successful commercialization of molten carbonate fuel cells (MCFCs). Microencapsulation of the NiO cathode has been adopted as a surface modification technique to increase the stability of NiO cathodes in the carbonate melt. The material used for surface modification should possess thermodynamic stability in the molten carbonate and also should be electro catalytically active for MCFC reactions. A simple first principles model was developed to understand the influence of exchange current density and conductivity of the electrode material on the polarization of MCFC cathodes. The model predictions suggest that cobalt can be used to improve the corrosion resistance of NiO cathode without affecting its performance. Cobalt was deposited on NiO cathode by electroless deposition. The morphology and thermal oxidation behavior of Co coated NiO was studied using scanning electron microscopy and thermal gravimetric analysis respectively. The electrochemical performance of cobalt encapsulated NiO cathodes were investigated with open circuit potential measurement and current-potential polarization studies. These results were compared to that of bare NiO. The electrochemical oxidation behavior of cobalt-coated electrodes is similar to that of the bare NiO cathode. Dissolution of nickel into the molten carbonate melt …
Date: September 30, 2000
Creator: White, Dr. Ralph E.
Object Type: Report
System: The UNT Digital Library
Identification and temporal behavior of radical intermediates formed during the combustion and pyrolysis of gaseous fuels: Kinetic pathways to soot formation. Final performance report, July 1, 1997 - September 30, 2000 (open access)

Identification and temporal behavior of radical intermediates formed during the combustion and pyrolysis of gaseous fuels: Kinetic pathways to soot formation. Final performance report, July 1, 1997 - September 30, 2000

A shock tube coupled to a time-of-flight mass spectrometer has been employed to analyze the dynamic behavior of reactants, products, and intermediates in those reaction systems which are most pertinent to understanding the chemistry attendant to the soot formation process. The measurement of the decay rates of the reactants, the rate of formation of intermediates and products have been used to determine rate constants over a wide temperature range. Recent examples include the pyrolyses of allene, propyne, pyrazine, pyrimidine, pyridine, acetylene, furan, cyclopentadiene, and methylcyclopentadiene.
Date: September 30, 2000
Creator: Kern, Ralph D.
Object Type: Report
System: The UNT Digital Library
Coal/Polymer Coprocessing With Efficient Use of Hydrogen (open access)

Coal/Polymer Coprocessing With Efficient Use of Hydrogen

The final project period was devoted to investigating the binary mixture pyrolysis of polypropylene and polystyrene. Their interactions were assessed in order to provide a baseline for experiments with multicomponent mixtures of polymers with coal. Pyrolysis of polypropylene, polystyrene and their binary mixture was investigated at temperatures of 350 C and 420 C with reaction times from 1 to 180 minutes. Two different loadings, 10 mg and 20 mg, were studied for neat polypropylene and polystyrene to assess the effect of total pressure on product yields and selectivities. For neat pyrolysis of polypropylene, total conversion was much higher at 420 C, and no significant effect of loading on the total conversion was observed. Four classes of products, alkanes, alkenes, dienes, and aromatic compounds, were observed, and their distribution was explained by a typical free radical mechanism. For neat polystyrene pyrolysis, conversion reached approximately 75% at 350 C, while at 420 C the conversion reached a maximum around 90% at 10 minutes and decreased at longer times because of condensation reactions. The selectivities to major products were slightly different for the two different loadings due to the effect of total reaction pressure on secondary reactions. For binary mixture pyrolysis, the overall …
Date: September 30, 2000
Creator: Broadbelt, Linda J.; DeWitt, Matthew J. & Wong, Hsi-Wu
Object Type: Report
System: The UNT Digital Library
PCGAP: Users Guide and Algorithm Description (open access)

PCGAP: Users Guide and Algorithm Description

PCGAP is a software package, which was written to provide gamma-ray pulse height spectrum analysis on a personal computer platform using the Windows NT operating system. It is a collection of programs, which provide a wide range of operability extending from the single user environment to the general purpose counting room. Included in the package are necessary data structures and libraries used to compute quantitative radionuclide concentrations. PCGAP also contains techniques to decontaminate photopeak interferences; determine activity concentrations for radionuclides independent of their associated spectral photopeak size; and three methods to determine the energy scale of a spectrum. PCGAP performs a non-linear least squares fitting of a Gaussian function to spectral photopeaks. The fitting algorithm can fit up to five concurrent photopeaks using a common spectral background. The package includes a program that will automatically locate spectral photopeaks, fit them to a Gaussian fu nction, identify the radionuclides associated with the found photopeaks, and compute a net activity concentration, and for an 8K spectrum do it in less than 30 seconds on a reasonably configured PC. PCGAP also includes a program which allows the operator to manually (using mouse clicks) identify photopeak locations, fit limits and background positions, initiate a …
Date: September 30, 2000
Creator: Killian, E.W. & Hartwell, J.K.
Object Type: Report
System: The UNT Digital Library
Hydrologic Behavior of Two Engineered Barriers Following Extreme Wetting (open access)

Hydrologic Behavior of Two Engineered Barriers Following Extreme Wetting

Many engineered barriers are expected to function for hundreds of years or longer. Over the course of time, it is likely that some barriers will experience infiltration to the point of breakthrough. This study compares the recovery from breakthrough of two storage- evapotranspiration type engineered barriers. Replicates of test plots comprising thick soil and capillary/biobarrier covers were wetted to breakthrough in 1997. Test plots were kept cleared of vegetation to maximize hydrologic stress during recovery. Following cessation of drainage resulting from the wetting irrigations, water storage levels in all plots were at elevated levels compared to pre-irrigation levels. As a result, infiltration of melting snow during the subsequent spring overloaded the storage capacity and produced drainage in all plots. Relatively rapid melting of accumulated snowfall produced the most significant infiltration events each year during the study. Capillary barriers yielded less total drainage than thick soil barriers. By limiting drainage, capillary barriers increased water storage in the upper portions of the test plots, which led to increased evaporation from the capillary barrier plots compared to thick soil plots. Increased evaporation in the capillary barrier plots allowed more water to infiltrate in the second season following the wetting tests without triggering drainage. …
Date: September 30, 2000
Creator: Porro, I.
Object Type: Report
System: The UNT Digital Library
Energy Efficiency Building Code for Commercial Buildings in Sri Lanka (open access)

Energy Efficiency Building Code for Commercial Buildings in Sri Lanka

1.1.1 To encourage energy efficient design or retrofit of commercial buildings so that they may be constructed, operated, and maintained in a manner that reduces the use of energy without constraining the building function, the comfort, health, or the productivity of the occupants and with appropriate regard for economic considerations. 1.1.2 To provide criterion and minimum standards for energy efficiency in the design or retrofit of commercial buildings and provide methods for determining compliance with them. 1.1.3 To encourage energy efficient designs that exceed these criterion and minimum standards.
Date: September 30, 2000
Creator: Busch, John; Greenberg, Steve; Rubinstein, Francis; Denver, Andrea; Rawner, Esther; Franconi, Ellen et al.
Object Type: Report
System: The UNT Digital Library
State of Idaho INEEL Oversight Program - Final Progress Report - 01/01/1996 - 09/30/2000 (open access)

State of Idaho INEEL Oversight Program - Final Progress Report - 01/01/1996 - 09/30/2000

The primary goal is to maintain an independent, impartial, and qualified State of Idaho INEEL Oversight Program to assess the potential impacts of present and future Department of Energy (DOE) activities in Idaho; to assure the citizens of Idaho that all present and future DOE activities in Idaho are protective of the health and safety of Idahoans and the environment; and to communicate the findings to the citizens of Idaho in a manner which provides them the opportunity to evaluate impacts of present and future DOE activities in Idaho. This will be accomplished through primary technical work activities and providing clear, factual data and other information to the public.
Date: September 30, 2000
Creator: Trever, Kathleen
Object Type: Report
System: The UNT Digital Library
Petawatt Laser Data Analysis and Technology Development (open access)

Petawatt Laser Data Analysis and Technology Development

The Petawatt (PW) laser beam line at the LLNL Nova laser facility was unique in the world in supplying an order of magnitude higher power (1PW in pulses of 500 fs duration) than lasers elsewhere. Focused to intensities reaching 3 x l0{sup 20} Wcm{sup -2}, it opened up a new regime of experimental science where free electron energies in the light wave are strongly relativistic. After full operational capability of the PW beam-line was reached, close to 25% of the operation of the Nova facility was dedicated to PW shots for two years, prior to the shut down of Nova in May 1999. A wealth of novel scientific data was obtained and it motivated the primary objective of this June 1 to Oct. 1, 1999 LDRD, which was to complete systematic analysis of the PW laser data. This was done by the team, which had conducted the experiments working with associated experts in theoretical modeling of the complex physical phenomena. A second objective was to develop a key new technology of large area transmission gratings needed for the next step to higher energy PW laser development. This work was done by the team, which developed the reflective grating technology.
Date: September 30, 2000
Creator: Key, M. H. & Perry, M. D.
Object Type: Report
System: The UNT Digital Library
MICROBIAL TRANSFORMATIONS OF PLUTONIUM AND IMPLICATIONS FOR ITS MOBILITY. (open access)

MICROBIAL TRANSFORMATIONS OF PLUTONIUM AND IMPLICATIONS FOR ITS MOBILITY.

The current state of knowledge of the effect of plutonium on microorganisms and microbial activity is reviewed, and also the microbial processes affecting its mobilization and immobilization. The dissolution of plutonium is predominantly due to their production of extracellular metabolic products, organic acids, such as citric acid, and sequestering agents, such as siderophores. Plutonium may be immobilized by the indirect actions of microorganisms resulting in changes in Eh and its reduction from a higher to lower oxidation state, with the precipitation of Pu, its bioaccumulation by biomass, and bioprecipitation reactions. In addition, the abundance of microorganisms in Pu-contaminated soils, wastes, natural analog sites, and backfill materials that will be used for isolating the waste and role of microbes as biocolloids in the transport of Pu is discussed.
Date: September 30, 2000
Creator: Francis, A. J.
Object Type: Book
System: The UNT Digital Library
Alternative Fuels and Chemicals From Synthesis Gas Technical Progress Report: Number 24 (open access)

Alternative Fuels and Chemicals From Synthesis Gas Technical Progress Report: Number 24

The overall objectives of this program are to investigate potential technologies for the conversion of synthesis gas to oxygenated and hydrocarbon fuels and industrial chemicals, and to demonstrate the most promising technologies at DOE's LaPorte, Texas, Slurry Phase Alternative Fuels Development Unit (AFDU). The program will involve a continuation of the work performed under the Alternative Fuels from Coal-Derived Synthesis Gas Program and will draw upon information and technologies generated in parallel current and future DOE-funded contracts.
Date: September 30, 2000
Creator: Tijrn, Peter J.
Object Type: Report
System: The UNT Digital Library
Advanced Hot Gas Filter Development (open access)

Advanced Hot Gas Filter Development

DuPont Lanxide Composites, Inc. undertook a sixty-month program, under DOE Contract DEAC21-94MC31214, in order to develop hot gas candle filters from a patented material technology know as PRD-66. The goal of this program was to extend the development of this material as a filter element and fully assess the capability of this technology to meet the needs of Pressurized Fluidized Bed Combustion (PFBC) and Integrated Gasification Combined Cycle (IGCC) power generation systems at commercial scale. The principal objective of Task 3 was to build on the initial PRD-66 filter development, optimize its structure, and evaluate basic material properties relevant to the hot gas filter application. Initially, this consisted of an evaluation of an advanced filament-wound core structure that had been designed to produce an effective bulk filter underneath the barrier filter formed by the outer membrane. The basic material properties to be evaluated (as established by the DOE/METC materials working group) would include mechanical, thermal, and fracture toughness parameters for both new and used material, for the purpose of building a material database consistent with what is being done for the alternative candle filter systems. Task 3 was later expanded to include analysis of PRD-66 candle filters, which had been …
Date: September 30, 2000
Creator: Connolly, E. S. & Forsythe, G. D.
Object Type: Report
System: The UNT Digital Library
Selective Oxidation of Benzene to Phenol. Final Report (open access)

Selective Oxidation of Benzene to Phenol. Final Report

Direct catalytic oxidation of commodity aromatics to phenolic compounds was studied by a team from Akzo Nobel Chemicals, Argonne National Lab., and Northwestern University. Results did not exceed previously published performance. The object of the project was to selectively oxidize benzene to phenol using a conventional oxidant.
Date: September 30, 2000
Creator: Sherif, F.; Kung, H. & Marshall, C.
Object Type: Report
System: The UNT Digital Library
Novel Mass Spectrometry Mutation Screening for Contaminant Impact Analysis (open access)

Novel Mass Spectrometry Mutation Screening for Contaminant Impact Analysis

Due to the limited budget of waste clean-up for all DOE contamination sites, it is critical to have a sound risk analysis with strong scientific basis to set priority for waste clean-up. In the past, the priority was often determined mostly by the type and quantity of pollutants and the observation of cancer rate increase. Since human cancers can be caused by various reasons in addition to environmental contamination, a rigorous study to find the relationship between specific contaminants and cancer is critically important for setting up the priority for waste clean-up. In addition, a contaminated site usually contain many different pollutants. However, it can be only a few specific pollutants are carcinogenic chemicals which are responsible for most cancers. Clean-up of small quantity of critical pollutants instead of the entire pollutant site can save significant decontamination cost. Since a few anti-tumor genes such as p53 and ras genes are highly conserved among various animals and mutation of these genes have been associated with many human cancers, it is very valuable to find the relationship between specific contaminant and specific cancer. Since it is not possible to pursue any human on the relationship of cancer and specific pollutant under well …
Date: September 30, 2000
Creator: Chen, Winston Chung-Hsuan & Lee, Kai-Lin
Object Type: Report
System: The UNT Digital Library
Rational Design of Metal Ion Sequestering Agents (open access)

Rational Design of Metal Ion Sequestering Agents

The discriminate bonding of metal ions is a challenge to the synthetic chemist and a phenomenon of considerable practical importance.1 An important feature of many technical applications is the specific or preferential binding of a single metal ion in the presence of many metals. Examples range from large-volume uses (e.g. ferric EDTA as a plant food, calcium complexing agents as water softeners or anticaking formulations) to very high technology applications (technetium complexation in radiopharmaceuticals, synthetic metalloenzymes). We are interested in efficient and discriminate binding of actinides for waste stream remediation. Actinides represent a major and long-lived contaminant in nuclear waste. While the separation of actinides from other radioactive components of waste, such as Sr and Cs, is relatively well established, the separation of actinides from each other and in complex solutions (e.g. those found in tank wastes) is not as well resolved. The challenge of designing metal-specific (actinide) ligands is facilitated by examples from nature. Bacteria synthesize Fe(III)-specific ligands, called siderophores, to sequester Fe(III) from the environment and return it to the cell. The similarities between Fe(III) and Pu(IV) (their charge-to-size ratios and acidity), make the siderophores prototypical for designing actinide-specific ligands. The chelating groups present in siderophores are usually …
Date: September 30, 2000
Creator: Raymond, Kenneth N.
Object Type: Report
System: The UNT Digital Library
LOW TEMPERATURE CATHODE SUPPORTED ELECTROLYTES (open access)

LOW TEMPERATURE CATHODE SUPPORTED ELECTROLYTES

This project has three main goals: Thin Films Studies, Preparation of Graded Porous Substrates and Basic Electrical Characterization and testing of Planar Single Cells. During this time period substantial progress has been made in developing low temperature deposition techniques to produce dense, nanocrystalline yttrium-stabilized zirconia films on both dense oxide and polymer substrates. Microstructural changes in unsupported nanocrystalline yttrium stabilized zirconia (ZrO{sub 2}:16%Y, or YSZ) thin films were examined as a function of temperature and annealing time in order to determine the grain growth exponent and the mechanisms of pinhole formation. Grain growth and pinhole formation were measured using high resolution transmission electron microscopy (HRTEM), normal imaging mode transmission electron microscopy (TEM), electron diffraction, and energy dispersive X-ray microanalysis (EDS). Grain growth was found to vary with a time exponent of about one half before pinhole formation and about one third after. Pinhole formation in 70 nm thick films occurred at temperatures near 600 C, corresponding to a grain size of about 15 nm, or a grain size to film thickness ration of approximately 0.25. The deposition of films on porous substrates is hampered by the penetration of the polymer precursor solution into the substrate whose pores as > 0.2 …
Date: September 30, 2000
Creator: Anderson, Harlan U.; Huebner, Wayne & Kosacki, Igor
Object Type: Report
System: The UNT Digital Library
System Design of a Natural Gas PEM Fuel Cell Power Plant for Buildings (open access)

System Design of a Natural Gas PEM Fuel Cell Power Plant for Buildings

The following conclusions are made based on this analysis effort: (1) High-temperature PEM data are not available; (2) Stack development effort for Phase II is required; (3) System results are by definition preliminary, mostly due to the immaturity of the high-temperature stack; other components of the system are relatively well defined; (4) The Grotthuss conduction mechanism yields the preferred system characteristics; the Grotthuss conduction mechanism is also much less technically mature than the vehicle mechanism; (5) Fuel processor technology is available today and can be procured for Phase II (steam or ATR); (6) The immaturity of high-temperature membrane technology requires that a robust system design be developed in Phase II that is capable of operating over a wide temperature and pressure range - (a) Unpressurized or Pressurized PEM (Grotthuss mechanism) at 140 C, Highest temperature most favorable, Lowest water requirement most favorable, Pressurized recommended for base loaded operation, Unpressurized may be preferred for load following; (b) Pressurized PEM (vehicle mechanism) at about 100 C, Pressure required for saturation, Fuel cell technology currently available, stack development required. The system analysis and screening evaluation resulted in the identification of the following components for the most promising system: (1) Steam reforming fuel processor; …
Date: September 30, 2000
Creator: Joe Ferrall, Tim Rehg, Vesna Stanic
Object Type: Report
System: The UNT Digital Library